Question

What is the value of x that makes AB |I CD?

Answer 1

30°

30 is the value of x that’s makes AB//CD.

Explanation:

the angles of measures 2x + 40 and 3x + 10 are two Alternate interior angles

If these two angle were congruent then the lines AB and CD

would be parallel .

2x + 40 = 3x + 10

⇔ 40 - 10 = 3x - 2x

⇔ 30 = x

⇔ x = 30

Answer 2

30

In order for AB to be parallel to CD, the two labeled angles must be equivalent. If we set the two expressions equal to each other and solve for x, we can find the value of x that makes angle AEF and angle EFD equivalent and therefore the lines AB and CD parallel.

2x + 40 = 3x + 10
40 = x + 10
30 = x

If the value of x were 30, both angles would be 100°