Question 259624

We can use the Pythagorean theorem.
a^2+b^2=c^2 
10^2+15^2=20^2
100+225=400
325=400
not a right triangle
15^2+ 18^2= 24^2
also divide the sides by 3
5^2+6^2=8^2
25+36=64
61=64
not a right triangle
There are special right triangles
http://en.wikipedia.org/wiki/Special_right_triangles