Question

In circle O below, how long is NM?

Answer 1

pythagoras theorem

Answer 2

use the pythagorean theorem :
MN = MO^2 - ON^2

Answer 3

* MN^2

Answer 4

7^2+25^2=(NM)^2
49+625=(NM)^2
(NM)^2=674
NM=sqr(674)