A triangle has sides with lengths of 72 millimeters, 90 millimeters, and 54 millimeters. Is it a right triangle?

Yes, it is a right triangle.

Step-by-step explanation:

a^2+b^2=c^2

The longest side is the hypotenuse so c^2 would be 90.

72^2+54^2=90^2

72 and 54 can be either a or b.

Solve for all exponents: 5184+2916=8100.

That equation is true, so the triangle is a right triangle.

38.5

step-by-step explanation:

lets say, first number = r

second number = 3r+7

total = 49

(r)+(3r+7)= 49

4r+7 = 49

4r = 42

r = 42/4

r= 10.5

3r+7 = 3(10.5)+7 = 38.5

hope this