Question

Question #e5255

Answer 1

It is an obtuse angle triangle.

Explanation:

Conditions for a triangle to be right angle or acute angle or obtuse angle, given the three sides.

Given a = 12, b = 9, c = 4

Right Angle #Delta : a^2 = b^2 + c^2

Acute Angle `Delta : a^2 < b^2 + c^2`

Obtuse Angle `Delta : a62 > b^2 + c^2`

In the given sum,

`a^2 = 12^2 = 144, b^2 = 9^2 = 81, c^2 = 4^2 = 16`

Since `144 > (81 + 16)`, it is an obtuse angle triangle.