Question

A triangle has side lengths of 18 cm , 80 cm, and 81 cm. Is this triangle Obtuse Acute or Right. And please explain how you got your answer so i can check it

Answer 1

acute because its not 90 degrees and it isnt greater then 90

Answer 2

Answer:

The triangle is acute.

Step-by-step explanation:

Given : A triangle has side lengths of 18 cm , 80 cm, and 81 cm.

To find : Is this triangle Obtuse Acute or Right.                

Solution :

According to property of triangle,

If the square of larger side of triangle is equating to the sum of square of smaller side

If $a^2=b^2+c^2$ the triangle is right triangle

If $a^2<b^2+c^2$ the triangle is acute triangle        

If $a^2>b^2+c^2$ the triangle is obtuse triangle        

where, a is the larger side and b,c are the smaller side

Let a=81 , b=80, c=18

LHS-

$a^2=81^2=6561$

RHS -

$b^2+c^2=80^2+18^2\\b^2+c^2=6400+324=6724$

LHS <RHS

Means $a^2<b^2+c^2$

Therefore, The triangle is acute.