Question

Work out the value of x

2x



7x

this is a Co-intirior angle

Answer 1

Explanation:

The sum of co-interior angle = 180°

Now,

2x + 7x = 180°

9x = 180°

x = 180° ÷ 9

x = 20°

Answer 2

x = 20

Explanation:

Co-interior angles (also called same-side interior angles) are two angles that are on the same side of the transversal and on the interior of (between) the two parallel lines.

Same-side interior angles theorem: If two parallel lines are cut by a transversal, then the same side interior angles are supplementary (add up to 180º).

Therefore, if 2x and 7x are co-interior:

⇒ 2x + 7x = 180

⇒ 9x = 180

⇒ x = 20