Question

which triangle is not congruent to the other three triangles?

Explanation:

Step1: Recall the definition of congruent triangles

Congruent triangles are triangles that have the same size and shape. This means that their corresponding sides are equal in length and their corresponding angles are equal in measure. We can visually compare the triangles by looking at the lengths of their sides (the overall "shape" and "size" of the triangle).

Step2: Compare the triangles

The first three triangles appear to have a similar "compact" shape, with sides of relatively similar lengths (visually, their overall dimensions seem to match). The fourth triangle, however, looks more "stretched out" or elongated. Its sides seem to be of different lengths compared to the first three triangles, especially in terms of the length of the base or the other sides when visually inspected. So, the fourth triangle does not have the same size and shape as the other three, meaning it is not congruent to them.

Answer:

The fourth triangle (the bottom - most one)