taking matches talking tall tall objects taller tan tan 15 degrees tan inverse tan(3x) tan3x tan^-1 tangent tangent a b tangent circle tangent circles tangent coins tangent line tangent line passes through a point tangent lines tangent lints tangent of 15 degrees tangent to a circle tangent to a curve tangent to y = x^3 tangents tangents to a circle tangents to a curve tangrams tank tank radius tank volume tanker tanks tape taper tapered cylinder tapered pole tapes tapestry rod tartelette taux à déterminer tax tax calculation tax form tax rates taxable amount taxes taxi taxicab geometry taylor taylor polynomial taylor series teacher teachers teaching teaching math teaching operations team roster team schedule team selection teams teams of 4 teasers teaspoons technique teepee teeth telephone telephone banking telephone charges telephone keypad telephone pole telephones telescope television screen telling time temperature temperatures ten ten acres ten digit number ten percent ten stools ten thousand ten-digits tennis tennis ball tennis balls tennis schedule tens tens digit tension tensoriel tent tenths term term number terminal zeros terminating decimal terminating decimals terminologie mathematique terminology termonology terms terre terrible question tessellation tessellations tesser tesseract test test drive test of hypothesis test scores test statistic test tube tests tethered goat tetraèdre régulier tetradecagon tetraedre tetraedre regulier tetrahedra tetrahedral numbers tetrahedral polygon tetrahedron tetrahedron volume tetrahedrons texas textbook thales thank you gifts thanksgiving the 20 kilometer walk the angle between two planes the area of an irregular polygon the binomial theorem the birthday problem the central arc of a circle the curious world of probabilities the delian problem the diameter and circumference of a circle the diameter of the base of a cone the equation of a line the factor theorem the four colour theorem the game of 24 the inverse of a function the isoperimetric theorem the law of cosines the leaning tower of pisa the method of elimination the number of standard deviations the number of subsets of a set the problem of apollonius the pythagorean theorem the quadratic formula the salinon of archimedes the square root of 2 the square root of 3 the square root of two the substitution method the sum of fractions the sum of repeating decimals the sum of two numbers the surface area of a sphere the theorem of menelaus theme day theorem theorem of pythagoras theorem of pythagoreas theory thermal thermal expansion thermometer thief things equal to the same thing thinking mathematically thinking outside the box third degree third derivatives third difference third side third vertex thirteen thirty seven thousand thousands thousandths thread three balls three by 3 three chickens three chickens weighed in pairs three chords three circles three citcles three coins three consecutive integers three consecutive natural numbers three consecutive numbers three consecutive odd integers three consecutive positive integers three daughters problem three dice three digit three digit combinations three digit number three digit numbers three digits three dimensional three dimensional co-ordinate geometry three dimensional geometry three dimensional rectangle three dimensions three discounts three dots three equations three equations in three unknowns three fish three foursomes three fractions three goldfish three holes three jugs three jugs problem three letter three lines three numbers three partners three percentages three possibilities three pulley system three space three spheres three times a year three tumbler lock three unknowns three variables three-digit number three-digit numbers threesomes throwing a ball thunder ticket ticket revenue tide ties tile tiles tiling tiling a floor tilings tilted cylinder tilted cylindrical tank tilted drum tilted tank volume timber time time and a half time laps times timing tin can tip tipi tips tire wear tires to a circle toad tolerance tolerance limit toll booth ton tonnage tons tons of stone toonies toothpicks tootsie roll top cut off top half top soil topics topological transformation topology topsoil topsoil pile toronto torque torricelli's trumpet torus torus volume tossing coins total total cost total lot size total number total owed touch tournament tournaments tower tower height towers towers of hanoi puzzle town population townships toy toy chest toys tps track track schedule traduction traduire en anglais trailer train train problem train track train trip trains trajectory transcendental transfinite ordinals transformation transformation formulas transformations transition matrix transitive transitivity translate translated translation translation into english translations translators transmitters transom transporting bananas transposition error transversal trap trapeziod area trapezium trapezoid trapezoid area trapezoid inscribed in a circle trapezoid rule trapezoidal prism trapezoidal rule trapezoids trash traveling salesman travelling in opposite directions treasure tree tree diagram tree diagrams trees trench trench volume tri-meets triacontaedre triakis triakistetrahedron trial and error trials triange triangle triangle altitudes triangle angles triangle area triangle construction triangle equilateral triangle faces triangle height triangle in 3 space triangle inequality triangle inscribed in a circle triangle jokes triangle perimeter triangle proof triangle puzzle triangle shaped triangle side lengths triangle sides triangle vertex triangle vertices triangles trianguar pyramid triangular triangular box triangular ditch triangular field triangular garden triangular lot triangular numbers triangular pen triangular prism triangular prisms triangular pyramid triangular pyramids triangular shape triangular shaped garden triangular trough triangulation triannual trick trick question tricycles triennial trifecta trig trig equation trig functions trig identies trig identities trig identity trig in real life trig limit trig limits trig substitution triginometry trignometry trigonométrie trigonomerty trigonometric trigonometric equation trigonometric functions trigonometric identities trigonometric identity trigonometric substitution trigonometrie trigonometriques trigonometry trigonometry equation trigonometry identities trigonometry identity trigonometry in real life trigonomety trillion trillion seconds trillions triminoes trinity trinomial trinomials triple angle formula triple angle formulas triple product triple system triples trisect trisected trisecting an angle trisection triskaidecagon trois équations trois equations trois maisons trolls trough troy weight trrapezoid truck truck box truckloads true false true or false truncared cone truncated truncated cone truncated cone diameter truncated icosahedron truncated prism truncated pyramid truncated rectangular pyramid tsp tub volume tube tubes tulip bulbs tumblers tuna bots tunnel tuple turing turn over turtle tv tv screen tvq twelve twenty four twenty-four twice two two averages two binomials two boats two buildings two candles two cars two circles two circles inscribed in a rectangle two column proof two cones two consecutive numbers two consecutive odd integers two curves two dice two different prices two digit number two digit numbers two digits two dimensions two dogs two equations two equations in two unknowns two equations two unknowns two ferry boats two foursomes two graphs two inequalities two jugs two lines two lots two means two members two modes two negatives two nonlinear equations two numbers two overlapping circles two parabolas two people two percent two pieces of rope two points two poles two quadratic equations two rectangles two regression lines two sequences two step equation two tax rates two threesomes two trains two unknowns two variables two-column proof two-digit number two-digit numbers two-tiered gst typing a project tyres ug / l ug/l uhaul ul uluru umbrella un angle solide un cercle un compacted soil un hectolitre un lapin un lièvre et un chien un nombre entier un plan un prisme un prix un probleme de math un tétraèdre un tetraedre un triangle isocèle un triangle isocele un volume unbiased unbounded uncertainty uncompacted soil uncountable uncountable sets undecagon undecillion undefined undefined slope underestimation understanding math undertermined undetermined coefficients undirected graph une boule une journée une piscine une sortie une sphere une suite unfavorable unfavourable uniform acceleration uniform density function uniform distribution union uniqueness unit unit circle unit conversions unit cost unit fractions unit price unites uniting geometry and algebra units units conversion units digit units digit of a prime number units digits units of measurement universal universe unknown unknowns unlimited unmatched socks unpopular unrealistic problem unscramble unsolvable unsolved problem unusual occurrences upc number upper quartiles upstream urn us usa usage uses valentines valid argument valid proof value value of change value of concrete vapor trails variability variable variable equation variable expression variable expressions variable in the exponent variable power variable rectangle variables variance variances variant variation varies directly varies inversely varies jointly varietes vat vatican city vector vector addition vector diagram vector division vector geometry vector space vector spaces vectors vehicle collision velocity venn diagram venn diagrams verbal problem verify verifying vertex vertex angle vertex of a parabola vertical asymptote vertical asymptotes vertical height vertical line vertical line test vertical planes vertices verticies vial video games village of lies village of truth vinculum vinegar virgule visible visitor visual angle visual representation visual thinking vocation voitures voltaique volume volume and scale factor volume calculator volume cylinder volume d'une calotte ellipsoidale volume de la boule volume in a pipe volume in cubic yards volume of a box volume of a concrete wall volume of a cone volume of a cone without calculus volume of a cube volume of a cylinder volume of a cylindrical tin volume of a freezer volume of a frustum volume of a hexagonal box volume of a hexagonal prism volume of a hose volume of a lake volume of a person volume of a prism volume of a pyramidal frustum volume of a sphere volume of a tank volume of a tetrahedron volume of a triangular pyramid volume of a triangular trough volume of a truncated rectangular pyramid volume of a wedge volume of air flowing in windpipes volume of an attic volume of revolution volume problem volume relationships volumes volumes of revolution volune voronoi diagrams vrd vulume wages wagon wheel walking walking speed walking towards each other wall wall covering wall paper wallcovering wallet wallpaper wallpapering washer method washing machine watecolours water water bill water content water density water depth water height water in a trough water jugs water level water lily water lines water main water storage water tank water trough water usage watercolors watermelon waterway watts wax weather wedding wedge wedge volume week weeks weigh weighing weight weight loss weight of dirt weight of two dogs weighted average weights welding well well house cover well width west wet clay wet clay density wet sand whale what is calculus? what percentage wheel wheel speed when would one change the direction of the inequality sign? which is larger whole whole numbers why learn math? The 150 MW Andasol solar power station is a commercial parabolic trough solar thermal power plant, located in Spain...transition from coal, oil, and gas to wind, solar, and geothermal energy is well under way.

Renewable energy continued its rapid growth in 2015, providing multiple benefits.

There was a new record set for installed wind and photovoltaic capacity (64GW and 57GW) and a new high of US$329 Billion for global renewables investment.

Several mining tragedies globally have underscored the human toll of the coal supply chain.

New EPA initiatives targeting air toxics, coal ash, and effluent releases highlight the environmental impacts of coal and the cost of addressing them with control technologies.

These methods include promoting renewable sources such as solar power and wind power, requiring utilities to use more renewable energy, and providing tax incentives to encourage the development and use of such technologies.

It is expected that renewable energy investments will pay off economically in the long term.

With situations involving decay, the rate of growth is always negative.

The half-life of a substance is the amount of time it takes for half of that substance to decay.

Third-generation technologies require continued R&D efforts in order to make large contributions on a global scale and include advanced biomass gasification, hot-dry-rock geothermal power, and ocean energy.