Question

You are given the sides of a triangle and need to determine if the triangle is acute, obtuse or right.

8. Sides have lengths 9 in., 7 in., and 8 in.

9. Sides have lengths 36 ft., 39 ft., and 15 ft.

10. Sides have lengths 9 m, 33 m, and 41 m.

Could someone please explain how to do this. I don't want answers, I want to know how to do this.

Answer 1

I think question 8 wants works like this.

a^2 + b^2 = c^2

6^2 +7^2 = 8^2

36 + 49 = 64

But 36 + 49 does not equal 64, it equals 85.

So I'm left with C = 64 but A + B = 85.

Does that make this an obtuse or an acute triangle?