Question

A triangle ABC is inscribed in a circle, such that AB is a diameter. What are the measures of angles of this triangle if measure of arc BC = 134°

Answer 1

Answer:

∠C=90°

∠A=67°

∠B=23°

Step-by-step explanation:

For angle C:

  Thales' Theorem states that an angle inscribed across a circle's diameter is always a right angle.

  Therefore, since AB is the diameter(hypotenuse) then angle C is the right angle. (90°)

For Angle A:

  The measure of arc BC= 134 degrees. We can just use a formula for an inscribed triangle. ∠A = 1/2 (mBC)

  ∠A= (1/2)134

  ∠A= 77°

For angle B:

  All triangle angles all add up to 180. We can just subtract angles A and C from 180°:

  ∠B = 180-(90+67)

  ∠B = 23°