Question

The measure of ∠1 =

Answer 1

measure of ∠1 = 90°

Explanation:

Here we are given an angle 1 which is an angle in a semi circle.

We know that, any angle subtended by the diameter or the semi circle on any point of the circle is a right angled triangle.

In the given diagram, we have a straight line passing through O (the center point of the circle) and making an angle 1 at a point on the circle.

So it will be a right angle and so measure of ∠1 = 90°

Answer 2

∠1 = 90 degrees.

Explanation:

We have a theorem called Angle in a Semi-Circle that says the angle subtended by the diameter of circle on the circumference of circle is always 90 degrees.

In the given diagram, we can see the diameter of circle makes ∠1 on its circumference.

Using the above theorem, we can say the angle ∠1 would be 90 degrees.

Hence, ∠1 = 90 degrees.