Which is the best approximation for the measure of angle ABC?

Side AB = 20

Side BC = 10.5

Angle C is the right triangle

Angle B = x

We can find the approximate measurement of angle ABC and it is equal to 180°. The summation of all angles in a triangle is 180°.

Solving for x or angle B, we need to used Pythagorean theorem and SOH CAH TOA.

Solving for angle A:

sinA = 10.5/20

A = 31.67°

Solving for angle B:

180° = ∠C + ∠B + ∠A

180° = 90° + ∠B + 31.67

∠B = 58.33°

The x value is 58.33°.