Answer:
a = 45
b = 15
Explanation:
From the information given, you can deduce that both ΔPQR and ΔPSR are isosceles triangles that share base PR. This means that ∠a = ∠SRP because the base angles of an isosceles triangle are always congruent.
Because the vertex of ΔPSR is 90°, you know that the base angles add up to 90 because 180(sum of a triangle's angles) - 90 = 90. 90/2 = 45, so a = 45.
To find b, you need to subtract the base angle of ΔPSR from the base angle of ΔPQR. ΔPQR's base angle is 60, because 180 - 60 = 120 and 120/2 = 60. 60 - 45 = 15, so b = 15.