Answer:
∠B = 40°
Step-by-step explanation:
The given angle relations can be expressed in two equations.
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setup
A + B = 90° . . . . . . . . angles are complementary
A×(1 -20%) = B . . . . . B is 20% smaller
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solution
Using the second equation to substitute for B in the first equation, we get ...
A + 0.80A = 90° . . . . . . substitute for B
A = 90°/1.8 = 50° . . . . . collect terms, divide by the coefficient of A
B = A(0.80) = 40° . . . . find B from A
The measure of angle B is 40°.
