What does isosceles mean in geometry?
The word "isosceles" is, mostly, used referring to triangles with two sides equal in length
Here are major properties of isosceles triangles.
It divides our triangle into two right triangles that share a cathetus
These triangles are congruent by cathetus and hypotenuse and, therefore altitude
Consequently, two angles at the base of this isosceles triangle are also congruent.