Video Transcript
Consider the following triangle. Identify the legs of the triangle. Option (A), line segment ๐ด๐ต and line segment ๐ต๐ถ. Option (B), line segment ๐ด๐ต and line segment ๐ด๐ถ. Or option (C), line segment ๐ต๐ถ and line segment ๐ด๐ถ.
Letโs begin by looking at the triangle that has been drawn. Triangle ๐ด๐ต๐ถ has a side ๐ด๐ถ of three centimeters and two shorter sides each of
two centimeters. This means that this must be an isosceles triangle, because by definition an
isosceles triangle has two congruent sides. Line segments ๐ด๐ต and ๐ต๐ถ are the same length of two centimeters, so we can mark on
the diagram that these are congruent.
This also means that we can identify the legs of this isosceles triangle. The two congruent sides of an isosceles triangle are called the legs of the
triangle. That means that we can give the answer that the two legs of this isosceles triangle
are line segments ๐ด๐ต and ๐ต๐ถ, which was the answer given in option (A).
Although we werenโt asked for it here, the third side of an isosceles triangle is
referred to as the base. Note that this does not have to be the side which is horizontal at the bottom of the
triangle in the way we may typically have seen isosceles triangles drawn. It is simply the noncongruent third side.
