I cannot see the triangle. But the way to know if 2 triangles are similar is if they have the see angle measurements or if the ratio of all 3 sides to its matching similar side are equal.
So if one triangle has sides of 1, 2, 3 and another had 2, 4, 6 theirvsides all form the same ratio. Notice how I take one line at time.
1/2 = 2/4 = 3/6
so they are similar
