If the side opposite a 300 angle in a right triangle is 12.5 meters, how long is the hypotenuse?

side opposite to 30° is half the hypotenuse.

12.5 = 1/2 hypotenuse

hypotenuse = 12.5 × 2 = 25 m

-------------

I assume you meant to write 30 degree angle. In any 30 - 60 - 90 right triangle the ratio of the sides is

Opposite 30 degree = 1

Opposite 60 degree = squareroot(3)

Opposite 90 degree = 2

Therefore, the length of the hypotenuse is 12.5 * 2 = 25

Assuming that you mean a 30-degree angle, the hypotenuse is 25.0 meters.

(A 30-60-90 right triangle can result from bisecting an equilateral triangle. The short side is equivalent to half the side of the original equilateral triangle, and the hypotenuse is a side of it.)

30 deg angle?

the hypotenuse = 2* 12.5 = 25 m

you cant have a 300 degree angle in a right-angled triangle, as all angles must add up to 180degrees in a triangle...