Question

The sides of a triangle measure 18 inches, 25 inches, and 36 inches. To the nearest degree, what is the measure of the largest angle? A 113° C 157° B 147° D 159°​

Answer 1

Answer:

A. 113°

Explanation:

opposite of the largest side is the largest angle

a=18 b=25 c=36

law of cosines

largest angle= arccos((a^2+b^2-c^2)/2ab))

largest angle= arccos((18^2+25^2-36^2)/2*18*25))

largest angle= arccos(-347/900)

largest angle= arccos(-0.38555555555)

largest angle= 1.96660618 rad

1rad × 180/π = 57.296

1.96660618×180/π=

112.678234078