Triangle ABC is a right triangle, it’s side lengths are AC=41 CB=40 AB=9. What is angle C?

Answer 1

use the law of cosines

9^2=41^2+40^2-2(40)(41)cosC

81=1681+1600-3280cosC

81=3281-3280cosC

81-3281=-3280cosC

-3200=-3280cosC

-3200/(-3280)=cosC

0.9756098=cosC

use inverse cos finder on your calculator or look it up on the web

cos^-1C=0.9756098

C=12.68037203°

C=12° 40' 49.339"