Respuesta :

Answer:

15m

Step-by-step explanation:

to answer this question, we need to use pythagorean theorem. this theory says:

a² + b² = c²

so, let’s work out b.

a² + b² = c²

20² + b² = 25²

20 x 20 = 400. 25 x 25 = 625.

400 + b² = 625.

we want to solve for b, which means to get b in it’s own, so we are going to get rid of the 400 on both sides, leaving just b² on the one side.

625-400=225.

b² = 225

b = √225

b = 15 :)

hope this helps!!!!