Please help me get the answer

b = 40°

Step-by-step explanation:

Since PQ = RQ, then Δ PQR is isosceles

Thus the 2 base angles are congruent

∠ PRQ  = 180° - 140° = 40° ( adjacent angles are supplementary )

Then

∠ QPR = ∠ PRQ = b = 40°

40 degrees

Step-by-step explanation:

The image says that PQ=RQ which makes this triangle isosceles. To solve you must remember that in isosceles triangles the two base angles are always congruent. In this case, the two bottom angles are the bases. So we must first solve for m<QRP. To do this use complementary angles to make the equation m<QRP=180-140. So m<QRP=40 which means b=40 also.