9514 1404 393
Answer:
(a) ∠SPR = 70°
(b) ∠SRP = 30°
Step-by-step explanation:
The applicable relationships are ...
- the measure of an arc is twice the measure of the inscribed angle it subtends
- the sum of measures of the arcs of a circle is 360°
- the sum of measures of the angles of a triangle is 180°
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QR is subtended by 35° inscribed angle QPR, so is 2×35° = 70°.
PQ is subtended by 45° inscribed angle PSQ, so is 2×45° = 90°.
RS is 2×QR, so is 2×70° = 140°.
(a) Inscribed angle SPR is half the measure of arc RS, so is 140°/2 = 70°.
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(b) Arc SP is the remaining arc in the circle, so is ...
arc SP = 360° -arc PQ -arc QR -arc RS = 360° -90° -70° -140° = 60°.
Inscribed angle SRP is half the measure of arc SP, so is 60°/2 = 30°
