Question

The sides of an isosceles triangle are 5, 5, and 7. Find the measure of the vertex angle to the nearest degree.

Answer 1

do you know law of cosines

Answer 2

c2=a2+b2-2(ab) cos C

Answer 3

49=50-50cosC
1=50cosC
1/50=cosC
Then use a graphing calculator and plug this in
cos^-1(1/50) = 88.854 degrees

Answer 4

If you do not have a calculator with you for later then you can use this awesome tool http://www.calculatorsoup.com/calculators/geometry-plane/triangle-law-of-cosines.php

Answer 5

thanks

Answer 6

Hey

Answer 7

sin inverse 0.7