Question 401345
Let ∠PQR = x and ∠ABC = 90 - x (we can make this assumption since they're complementary)


Then, ∠PQR = 4∠ABC --> {{{x = 4(90-x)}}} --> {{{x = 360 - 4x}}} --> x = 72. Therefore ∠PQR = 72 and ∠ABC = 18 (degrees).