Question

What type of triangle is formed by the side lengths below? 7cm 9cm 11cm A. Acute B. Right C. Obtuse D. Cannot form a triangle

Answer 1

A. Acute

Explanation:

To start, determine whether you can form a triangle or not. In any triangle, the sum of any two sides must be greater than the third side. In this case, this holds true and we can definitely form a triangle.

Let
`c` be the longest side of the triangle and let
`a` and
`b` be the other two sides.

If
`a^2+b^2>c^2`, the triangle is acute.

If
`a^2+b^2=c^2`, the triangle is right.

If
`a^2+b^2<c^2`, the triangle is obtuse.

Substituting given information:

`7^2+9^2>11^2`, therefore the triangle is acute.