Question

In a triangle ABC, AB = 9 cm, BC = 40 cm. and AC = 41 cm, then the triangle is
1. Right angled
2. Obtuse angled
3. Acute angled
4. Equal angled

Answer 1

Correct Answer - Option 1 : Right angled

Given:

AB = 9 cm, BC = 40 cm. and AC = 41 cm

Formula used:

AC² = BC² + AB² 

AC is the longest side, AB and BC are the other two side of triangle.

Calculation:

According to the question,

AC2 = BC2 + AB2 

⇒ 41² = 40² + 9²

⇒ 1681 = 1600 + 81

⇒ 1681 = 1681

LHS = RHS 

Then, ABC is a Right angle triangle

∴ The triangle is Right angle triangle.