Question

ABCD is a parallelogram. The ratio of <A and <B of this parallelogram is 5:4. Find the measure of
<B​

Answer 1

Step-by-step explanation:

Ratio of ∠A and ∠B for given parallelogram is 5 : 4

Let the common multiple be x.

m∠A = 5x°and m∠B = 4x°

Now, m∠A + m∠B = 180° …

[Adjacent angles of a parallelogram arc supplementary]

∴ 5x° + 4x°= 180°

∴ 9x° = 180°

∴ x° = 20°

∴ m∠B = 4x°= 4 x 20° = 80°

∴ The measure of ∠B is 800.