Question

What type of triangle is defined by the following set of side lengths

11, 9 , 7



Acute


Obtuse


Right


Not a triangle

Answer 1

ACUTE TRIANGLE

Explanation:

If the sum of the squares of the two shorter sides of a triangle is greater than the square of the longest side, the triangle is acute. However, if the sum of the squares of the two shorter sides of a triangle is smaller than the square of the longest side, the triangle is obtuse.

Therefore, the triangle with sides 11, 9, and 7 is an acute triangle since 9² + 7² is greater than 11²

`{9}^(2) \: + \: {7}^(2) > \: {11}^(2) \\ 130 > 121`