Question

In the given figure, the value of x is

Options

•  12

•  15

•  20

•  30

Answer 1

The figure is as follows:

It is given that

 ∠2 = 90°

Also,

 ∠1 = (3X + 10)°       (vertically opposite angles)

Since, x°, ∠1and ∠2form a linear pair.

Therefore,

X +  ∠1 +  ∠2 = 180° 

X + (3x + 10° ) + 90°  = 180° 

                 4x + 100°  = 180° 

                              4x = 180°  -100° 

                              4x = 80° 

                              `x = (80° )/4`

                               x = 20°