Question

if $\triangle mnocong\triangle nmo$, what statement best describes triangle $mon$?
the triangle is scalene.
the triangle is equilateral.
the triangle is isosceles and possibly equilateral.
the triangle is isosceles but definitely not equilateral.

Explanation:

Since \(\triangle MNO\cong\triangle NMO\), by the property of congruent triangles, corresponding sides are equal. So \(MO = NO\). A triangle with at least two equal sides is isosceles. If \(MO = NO=MN\), then it is equilateral. So the triangle is isosceles and possibly equilateral.

Answer:

The triangle is isosceles and possibly equilateral.