Which triangle is a 30°-60°-90° triangle? 10
5
5/3
15
5
53
10
5
10/3
15
10
5/3

The first triangle is a 30 60 90 triangle.

Step-by-step explanation:

The sides of a 30 60 90 triangle measure x, 2x, and x.

You can see that the first triangle's legs satisfy these measures:

x = 5

x = 5

2x = 10

Hope this helps :)