Answer:
C. RTS
Explanation:
When two triangles are congruent, they will have congruent vertices, like each vertex has a partner.
Take a look at the shape of the triangle.
If you look at the triangle on the right, you can see it is almost like a right triangle.
"R" is at the right angle. "S" is on the short side and "T" is on the long side.
In the triangle on the left, "M" is at the right angle. "N" is on the short side and "O" is on the long side.
Thus, the pairs of congruent angles are:
M ≅ R
O ≅ T
N ≅ S
When you write the statement of congruence between triangles, order the letters by their congruent pair.
MON ≅ RTS