Based on the information you have given, this triangle must be a 30-60-90 because it’s right (90 degrees) and has an angle of 30 degrees. For a 30-60-90 triangle, the side lengths are as follows: hypotenuse=2x (twice as much as the shortest leg which is located across from the 30 degree angle), the shortest leg=x, and the side across from the 60 degree angle (the longer side)=x √3. So, if the hypotenuse=12 cm and angle A=30 degrees, then that means side A must be 6 cm 12=2x and solve for x 6=x
