A triangle with exactly two sides that are equal is known as?

A triangle with exactly two sides that are equal is known as an isosceles triangle. This classification is based on the lengths of the sides rather than the angles. In an isosceles triangle, the two equal sides are referred to as the legs, and the third side is known as the base.

This property not only helps in recognizing the triangle type but also leads to some unique characteristics. For example, the angles opposite the equal sides are also equal, which makes it possible to solve for unknown angles when performing geometric calculations.

In contrast, an equilateral triangle has all three sides equal, a scalene triangle has all sides of different lengths, and an obtuse triangle contains one angle that is greater than 90 degrees. Thus, understanding these distinctions clarifies why an isosceles triangle is defined specifically by having exactly two sides equal.