4. Given: D is the midpoint of BC
<1 = <2
Prove: ABAC is isosceles
E
ת
2.
B.

D. 34

Step-by-step explanation:

Because this is a right triangle we can use sin, cos, tan.

Use cosine because the values of the adjacent side and hypotenuse are already given.

cos(θ) = 72/87

Because we are solving for the angle measure (and not the measure of the side) we need to use inverse cos.

cos⁻¹ = 72/87

put into a calculator and answer is approximatelyn34 degrees.