Which triangle is a 30 -60 -90 degree triangle?

The first one

Step-by-step explanation:

short side: x=5

long side: x=5

hypotenues: 5·2=10

Sides of a 30°-60°-90° triangle:

short side: x

long side:

hypotenues: 2x

none of the above.

for one of the equations to be used in the process, there has to be a term in the equation since squared is .

since there is only a term in the first equation, we cannot derive a from completing the square.

solving with completing the square