Question

Find the value of x y, and z in the parallelogram below.

Answer 1

Let A be the angle of 79 degrees
B be the angle of (5y-4) degrees
C be the angle of (x+5) degrees
D be the angle of (9z-7) degrees
According to the property of parallelogram
Opposite angles are equal
We get, angle A = angle C
Since angle A = 79 degrees
And angle C = (x+5) degrees
We get, x+5=79
=> x=79-5=74.

Angle B = Angle D
(5y-4)=(9z-7)
Since there’s two variables here, we can’t use the property of “opposite angles are equivalent”
We have to use another property which is adjacent angles are equal
Therefore, we can find angle D
Angle D + Angle A=180
=> 9z-7 =180-79
z=108/9
z=12
Since (5y-4)=(9z-7)
Substitute z=12 in
We get, 5y-4=101
y= 105/5
y= 21
Therefore, x=74, y=21 and z=12.