Question

ABCD is a parallelogram. The ratio of ZA and ZB of this parallelogram is 5:4.
Find the measure of Z B.​

Answer 1

$\uparrow\uparrow\uparrow\uparrow\uparrow\uparrow$Check the attachment.

$\huge \bigstar$$\huge\bold{\mathtt{\purple{✍︎A{\pink{N{\green{S{\blue{W{\red{E{\orange{R✍︎}}}}}}}}}}}}}$$\huge \Rightarrow$

$\Large \bold \red{Solution:}\Downarrow$

The ratio of $\large\angle A$ to $\large\angle B$ is 5:4.

Let the common multiple of this ratio be $\large x$.

Then $\large\angle A=5x°$ and $\large\angle B=4x°$.

$\large\angle A+\angle B=180°$. ...(Interior angles)

∴ $\large 5x°+4x°=180°$ ∴$\large 5x+4x=180$

∴$\large9x=180°$ ∴$\large x \large\frac{180}{9}$ ∴ $\large x=20$

$\large\angle B=4x°=4×20°=80°$

$\Large\bold\green{Ans:}\Downarrow$

The measure of $\large\angle B$ is 80°.