Question

ABCD is a parallelogram the ratio of angle A and triangle angle B of this parallelogram is 5:4 find the measure of angle B.​

Answer 1

Answer:

80°

Step-by-step explanation:

Let the ratio be 5x:4x.

According to property of parallelogram, Angle A and Angle B are supplementary.

=> 5x+4x = 180°

=> 9x = 180°

=> x = 20°

Hence, angle B = 4×20° = 80°

Answer 2

∴∠A=5x

and∠B=4x

□ ABCD is a parallelogram.

∴∠A+∠B=180

∘

[Adjacent angle of parallelogram are supplementary]

∴5x+4x=180

∘

⇒9x=180

∘

⇒x=180/9

⇒x=20

∘

∠B=4x=4×20

∘

=80

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The measure of ∠B is 80