Question

ABCD is a parallelogram. Find mzB.

Answer 1

Answer: m∠B=121°

Explanation:

The opposite angles of the parallelogram are equal

Hence,

(10x-19)°=(9x-5)°

10x-19=9x-5

10x-19-9x=9x-5-9x

x-19=-5

x-19+19=-5+19

x=14

Hence,

m∠B=(9(14)-5)°

m∠B=(126-5)°

m∠B=121°

Answer 2

m∠B = 121°

Explanation:

`10x-19=9x-5`

`10x=9x+14` (add 19 on both sides)

`x=14` (subtract 9x on both sides)

`9(14)-5 = 126-5=121`