If you have a right triangle, you can use the Pythagorean theorem, which is a²+b²=c². (c is the longest side or the hypotenuse)
You plug in the shorter sides for a and b, then you square root the answer.
A 14m, 20m, 25m
14² + 20² = 25²
196 + 400 = 625
596 = 625 X
B 10cm, 6cm, 8cm
6²+8²=10²
36+64=100
100=100 So your answer is B