Question

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Answer 1

It is square root of 25^2 minus 20^2 = square root of 225 = 15

Answer 2

Alright, so when i show the work, would this be the way to write it out?
25^2 = a^2 +20^2
625 = a^2 + 400
225 = a^2

(b-15)(b+15)
=15, or =-15

b=15

Answer 3

Yes...!

Answer 4

You used b for a. Change that.

Answer 5

k thanks a lot, i greatly appreciate it.

Answer 6

a^2 = 225
a = +/- 15. However, because we are talking of triangle length, which can only be positive, it has to be +15.