Question

Which set of side lengths could be used to form a

right triangle?
7.5 in., 18 in., 21.5 in.
7.5 in., 18 in., 19.5 in.
7.5 in., 19.5 in., 21.5 in.
18 in., 19.5 in., 21.5 in.

Answer 1

All sides of a right triangle are different lengths.

The shortest being the leg in which is opposite to the smallest angle on the standard right triangle (30 degrees). The side with the longest length is always the hypotenuse (point a-c).

Therefore, both answer a and b are eliminated considering two sides of the triangle have equivalent lengths.

Answer: C

You can use the Pythagorean theorem to check your answer (a^2+b^2=c^2)