Question

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

Explanation:

Step1: Identify congruent triangles

By side - side - side (SSS) or side - angle - side (SAS) congruence criteria, we can see that $\triangle{JKL}\cong\triangle{LMN}$ from the given markings on the sides.

Step2: Use congruent - angle property

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

Answer:

72