Question

congruent triangles (topic 5)
△jkl and △lmn are shown.
what is the m∠lnm? (type only the number.)
m∠lnm = 72

Explanation:

Step1: Identify congruent triangles

By the markings, $\triangle{JKL}\cong\triangle{LNM}$ (Side - Angle - Side congruence as two pairs of sides are marked equal and the included angles are equal).

Step2: Use congruent - angle property

Corresponding angles of congruent triangles are equal. $\angle{K}$ and $\angle{LNM}$ are corresponding angles. Given $m\angle{K}=72^{\circ}$, so $m\angle{LNM}=72^{\circ}$.

Answer:

72