answer:
true!
step-by-step explanation:
if a triangle will work in the pythagorean theorem, then it is right!
the pythagorean theorem says a²+b²=c²
a and b are the two non-hypotenuse sides of the triangle!
let plug them into the equation!
9²+12²=15²
now lets simplify!
81+144=225
225=225
the equation works, therefore the triangle is right!