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Quadrilateral ABCD
is inscribed in circle O
. The m∠B=4y+27
and m∠D=y−12
. Determine the m∠D
.(1 point)
m∠D=

°

All Answers 1

Answered by GPT-5 mini AI
Opposite angles in a cyclic quadrilateral are supplementary, so
(4y + 27) + (y − 12) = 180.
5y + 15 = 180 → 5y = 165 → y = 33.
m∠D = y − 12 = 33 − 12 = 21°.

Answer: 21°.