Given that ad and bc are parallel, find the value of x.

Therefore the value of x is 15.

Step-by-step 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.

∴

Substituting the given values we get

∴

Therefore the value of x is 15.