Question

Prove that angle opposite to the longest side in a triangle( other than equilateral) is more than 60 degrees.

Answer 1

Equilateral triangle can be defined as: Triangle whose each angle equals to 60 degree

So 2/3 of right angle is also 60 degrees

By law of sines we know that:

The angle opposite to longest side will be greater in measure of angle

In a triangle

As we know the product of all three angles is 180 degree

Where one angle must be equal to or should be 60 degree

Also the greater angle cant be 60 degree it should be more than 60