Inscribed Angle Math Example 4
Follow the full solution, then compare it with the other examples linked below.
Example 4
hardQuadrilateral is inscribed in a circle. If , find . Then, if arc and arc , find .
Solution
- 1 Step 1: Use the property that opposite angles of a cyclic quadrilateral are supplementary: .
- 2 Step 2: Solve for : .
- 3 Step 3: To find , note it intercepts arc (the arc from to not containing ). Arc .
- 4 Step 4: Apply the Inscribed Angle Theorem: .
Answer
;
Opposite angles in a cyclic quadrilateral sum to 180° because they intercept supplementary arcs that together form the full circle (360°). The inscribed angle ADC intercepts the combined arc AB+BC = 206°, giving half of that as 103°.
About Inscribed Angle
An angle whose vertex lies on the circle and whose sides are chords of the circle. Its measure is exactly half the measure of the intercepted arc.
Learn more about Inscribed Angle →More Inscribed Angle Examples
Example 1 easy
An inscribed angle intercepts an arc of [formula]. What is the measure of the inscribed angle?
Example 2 mediumIn circle [formula], inscribed angle [formula] intercepts arc [formula]. If arc [formula], and arc [
Example 3 easyAn inscribed angle measures [formula]. What is the measure of its intercepted arc?