Determine the unknown angle measures of ADEF.Round to the nearest degree.m2D23.5m2 =24.3D33.8F

Question

asked May 15, 2023 210k views

1 Answer

Bobesh · Answer 1 · 2023-05-21T12:30:54+0000

Given:

The sides of the triangle ABC are given

a=7, c= 8 and b= 13.

To find

The angle C.

Step-by-step explanation:

To find angle C , use the cosine rule.

$c^2=a^2+b^2-2ab\cos C$

Substitute the values in the cosine rule.

$8^2=7^2+13^2-2*7*13\cos C$
64=49+169-182cosC

$182\cos C=49+169-64$
$182\cos C=154$
$\cos C=(154)/(182)$
$C=\cos ^(-1)(0.846)=32.2^(\circ)$

Answer :

Hence the angle C is obtained as 32.2 degree.