Question

ZA and B are supplementary angles. If mA (x - 9)° and

Answer 1

The measurement of  ∠B  is 168°

Given,

In the question:

Angle A and Angle B are supplementary angles.

If mA (x - 9)° and m/B= (7x + 21)°

To find the measure of ∠B

Now, According to the question;

What are supplementary angles?

Two angles are Supplementary when they add up to 180 degrees.

Now, ∠A+∠B = 180°

So,

⇒(x - 9)˚+(7x + 21)°=180°

=> 8x +12 = 180°

=> 8x = 180° - 12

=> 8x = 168

=> x = 168/8

=> x = 21

For the measure of ∠B :

∠B  = (7x + 21)

∠B = 7 x 21 + 21

∠B  = 168°

Hence, The measurement of  ∠B  is 168°

Learn more about Supplementary angles at:

brainly.com/question/13045673

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