Dare2solve | Two semicircles on a common reference line

This question was uploaded on 26/09/21 on social media accounts.

Two semicircles are drawn on the same horizontal line. Find the angle between lines drawn on the tangential points of the common tangent to the common point of the semicircles.

Solution 1:

Yellow angle (x):

\[x=180-(90-\alpha)-(\alpha)=90\]

Solution 2:

Yellow angle (x):

\[x=(90-\alpha)+(\alpha)=90\]

Puzzle related to Geometry, Circle, Triangle, Angle.