Question

A triangle has side lengths of 9 cm, 25 cm, and 33 cm. Classify it as acute, obtuse, or right.

Answer 1

Obtuse scalene triangle

Explanation:

Side 1: 9 cm

Side 2: 25 cm

Side 3: 33 cm

1. Find 9 squared, 25 squared, and 33 squared:

9 squared = 81

25 squared = 625

33 squared: 1089

Find sum of the squares of 2 smallest sides:

81 + 625 = 706

Longest Side Squared = 1089

706 < 1089

Hence, since 706 < 1089, aka sum of the squares of the smaller 2 sides < longest side squared - you have a obtuse scalene triangle

I used a triangle calculator, so yeah in advance you should probably just use one of those :)

Answer 2

Obtuse.

Explanation:

If sides are a b and c, with c the longest:

c^2 = a^2 + b^2 = Right triangle

c^2 < a^2 + b^2 = Acute ...

c^2 > a^2 + b^2 = Obtuse ...

33^2 = 1089

25^2 = 625

9^2 = 81

625 + 81 = 706

1089 > 706 so the triangle is obtuse.