Which statements are true? Select all that apply. Multiple select.

A)
If a2+b2=c2, then a triangle is a right triangle, and its legs are units long and b units long, and the hypotenuse is c units long.

B)
If a+b=c holds true, then a triangle is a right triangle.

C)
If a2+b2=c2 , then a+b+c .

D)
If a triangle is a right triangle, then a2+b2=c2 holds true.