Tag: inscribed angle

How to Prove the Central Angle – Inscribed Angle Theorem

When two secants intersect on the circle, it forms an inscribed angle. There are three cases in which the secants may be positioned as shown in the figure below. These positions form different cases for the central angle-inscribed angle relationship. So when you prove the theorem that the measure of the inscribed angle is half

Angle inscribed in a semicircle

To solve the two problems below you need to know 1) The area of a circle is Πr2, with r as radius and that the area of a semicircle is of course  half of the circle, ½Πr2 and 2) the angle  in a semicircle theorem. Problem 1 Prove that the area of the solid green semicircle