Question

take note postulate 1 - 8 angle addition postulate. if point b is in the interior of ∠aoc, then m∠aob + m∠boc = m∠aoc. 21. draw ∠abt with point l in the interior and ∠abl and ∠lbt. 22. complete: m∠abl + m∠ = m∠

Explanation:

Step1: Recall angle - addition postulate

If a point is in the interior of an angle, the sum of sub - angles equals the whole angle.

Step2: Apply to ∠ABT

Since L is in the interior of ∠ABT, m∠ABL + m∠LBT = m∠ABT.

Answer:

m∠ABL + m∠LBT = m∠ABT