Noticewhathappenswhenyou dividean equilateraltrianglein half.
Whenan equilateraltriangleis dividedinto two equalpartsusingan altitude,eachresultingright triangleis
a triangle.The hypotenuseof the resultingtrianglewas the side of the original,and the
shorterleg is half of an originalside.This is why the hypotenuseis alwaystwicethe lengthof the shorter
leg in a triangle.You can use this informationto solveproblemsaboutequilateraltriangles.
30º-60º-90ºTriangles
Anotherimportanttype of right trianglehas anglesmeasuring , , and. Just as you founda
constantratio betweenthe sidesof an isoscelesright triangle,you can find constantratioshere as well. Use
the PythagoreanTheoremto discovertheseimportantrelationships.
Example 3
Find the lengthof the missingleg in the followingtriangle.Use the PythagoreanTheoremto find your answer.