These figures
(graph uptop)

(a.) congruent but not similar.

(b.) congruent and similar.

(c.) similar but not congruent.

(d.) neither similar nor congruent.

C) Similar but not congruent

Step-by-step explanation:

These figures are similar not congruent because:

In order for a triangle to be congruent it has to be the same size and shape.

There is no such thing as congruent but not similar as if it's congruent it is similar.

However, in order for a triangle to be similar it must have the same shape( angles).

So we can see that both triangles are isoceles and the sides of each are in a ratio of 2:1. Meaning that the bigger triangle has sides that are exactly twice as large as the smaller trinage. This also means that the angles are equal. Hence they are similar but not congruent.

good luck!

cutie~