Every triangle has three sides and these three sides make three interior angles. That is what “tri-” means in the word “triangle”.
A geometric figure that has three sides and three angles is a triangle is the most fundamental defination that defines a triangle.
If we see an enclosed shape with three straight sides, it is a triangle.
However, we can classify a given triangle further into one of the several categories and this happens based on the length of its sides and measure of its angles.
