Question

question
answer attempt 1 out of 1
ab || dc
x =
select answer

Explanation:

Step1: Identify the relationship (consecutive interior angles)

Since \( AB \parallel DC \) and \( AD \) is a transversal, \( \angle A \) and \( \angle D \) are consecutive interior angles, so they are supplementary (sum to \( 180^\circ \)). Thus, \( 11x + (10x + 12) = 180 \).

Step2: Simplify the equation

Combine like terms: \( 11x + 10x + 12 = 180 \) → \( 21x + 12 = 180 \).

Step3: Solve for \( x \)

Subtract 12 from both sides: \( 21x = 180 - 12 = 168 \). Then divide by 21: \( x = \frac{168}{21} = 8 \).

Answer:

\( 8 \)