Question

QS is the bisector of PQR and RS is the bisector of <PRQ. If <P = 76°, find the size of QSR.​

Answer 1

∠ QSR = 128°

Explanation:

∠ SRQ = ∠ PRS = 26° ( RS is angle bisector ) , then

∠ PRQ = 2 × 26° = 52°

∠ PQR = 180° - (52 + 76)° ← angle sum of Δ PQR

∠ PQR = 180° - 128° = 52°

∠ SQR = ∠ SQP = 26° ( QS is angle bisector )

Then

∠ QSR = 180° - (26 + 26)° = 180° - 52° = 128°