Question

Given that AD and BC are parallel, find the value of x.

Answer 1

Therefore the value of x is 15.

Explanation:

Given:

AD || BC

m∠ B = (9x + 15)°

m∠ A = (3x - 15)°

To Find:

x = ?

Solution:

AD || BC ...............Given

If two lines are parallel and sum of the interior angles are supplementary.

i.e m∠ B and m∠ A are interior between Parallel lines.

∴
`\angle B + \angle C =180\\`

Substituting the given values we get

∴
`(9x + 15)+( 3x - 15)=180\\12x=180\\\\x=(180)/(12) \\\\\therefore x =15`

Therefore the value of x is 15.