Inscribed Quadrilateral Theorem Inscribed Quadrilateral Theorem: If quadrilateral is inscribed in a circle, then its opposite angles are supplementary. Note: All
the vertices of the quadrilateral must lie on the circle.
Example 1: Find the indicated measures. Step 1: Determine if the all the vertices of the figure lie on the circle.
(2 +53)
No, not inscribed
R(15y + 17)
Yes, Inscribed
Step 2: Using the Inscribed Quadrilateral theorem, select a pair of opposite
angles and solve for the value y.
(5y + 3)
SPQ
LPQR
O LORS
O ZRSP
P
Step 3: Find the measure of each angle.
a. m SPQ=
b. mzPQR =
C. MZQRS =
d. mZRSP
Notes