Question

Prove that a triangle must have atleast two acute angles?

Answer 1

An acute angle is any angle that is less than 90˚
An obtuse angle is any angle that is more than 90˚ and is less than 180˚

The sum of the angles in a triangle is always 180˚. If we have two right angles, or two obtuse angles, or a right angle and an obtuse angle, we will either go over the limit of `180˚`, or not have room for another angle, and a triangle must always have 3 sides and 3 angles.

Therefore, only one obtuse or right angle may be used, which means that the other two angles will be acute. This means that there will also be cases where there are no obtuse or right angles, and all three angles are acute.

Hopefully this helps!