When two triangles are similar, their corresponding angles are equal.
So, the first step to solve the exercise is to find the measure of the missing angle in each triangle.
We know that the sum of the interior angles of a triangle is 180. Then, we have:
• Measure of angle R
• Measure of angle U
As we can see, the corresponding angles of the triangles RST and UVW are not equal.
Therefore, the triangles are not similar.