Question

What is the measure of angle c?​

Answer 1

Answer:

50 degrees

Step-by-step explanation:

Okay! So first off, because this is NOT a right triangle, we can't use soh cah toa. That means we can either use the law of sines or the law of cosines.

Because we only have sides here and no angles, we are forced to use the law of cosines.

c^2 = a^2 + b^2 − 2ab cos(C)

c = 6

b = 7.5

a = 6.5

36 = 6.5^2 + 7.5^2 - 2(6.5)(7.5)cos(C)

36 = 98.5 - 97.5cos(C)

-62.5 = -97.5cos(C)

0.641 = cos(C)

angle C = cos^-1(0.641)

angle C = 50.13 which is around 50 degrees

Remember! A dumb thing i always used to do in geometry was use radians instead of degrees, be sure to use degrees here because you are looking for degrees. Radians are for things involving not degrees, but PI.