Question

the opposite angle of a parallelogram ABCD are given a = to 3 x + 20 degree and c = to 2 x + 70 degree find the measure of each angle

Answer 1

Let angle A = 3 x + 20
Let angle B = 2 x + 70
sum of 4 interior angles = 360
[ angle ( A +B +C +D) = 360 ] ––––——eq^n ( 1.)
and
opp. angles of parallelogram are equal,
that is,
angle A = angle D, & angle B = angle C
from eq^n ( 1.)
angle (A +B +B +A) = 360
angle ( 2A +2B) = 360
2 (3 x +20) + 2( 2 x + 70 ) = 360
10 x + 180 = 360
10 x = 360 - 180
10 x = 180
x = 18.

angle A = 3 x + 20 = 74 degree
angle B = 2 x + 70 = 106 degree
angle C = 106 degree
angle D. = 74 degree.