Answer:
a= 75°
β= 30°
Explanation:
α = 75° This is because triangle PQR isosceles. Thus two of its angles are equal and these two are angle α and the one labelled 75.
β = 30° This is because angles in a triangle sum up to 180°. We already know two of these angles. To find β you say 180 - ( 75 × 2)
The answer becomes 30°.
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