Question

In a parallelogram ABCD, if angle A =(2x-20 degree), angle B =(y+15 degree , angle C=(x+40degree), then find the value of x and y .

Answer 1

In a parallelogram sum of adjacent angles are supplementary
A+B =180
2x-20+y+15=180
2x+y-5=180
y=180+5-2x
y=185-2x——(1)

B+C=180 ( In a parallelogram sum of adjacent angles are supplementary)

y+15+x+40=180

y+x+55=180
y+x=180-55
y+x=125
put eqn (1) in the above eqn
185-2x+x=125
185-125-2x+x=0
60-x=0
x=60

put x=60 in eqn (1)

y=185-2*60
y=185-120
y=65

x=60 and y=65