Yes, the Triangle Inequality Theorem applies to ALL triangles, including equilateral triangles.
The Triangle Inequality Theorem states that the sum of two sides must be greater than or equal to the length of the third remaining side. Let’s see an example:
Given an equilateral triangle with side measures: a, a, a. Let’s apply the Triangle Inequality Theorem:
a+a≥a
2a≥a
Let a be any side length. Let’s have a=5
2(5)≥5
10≥5.
So, we have just shown that this theorem is true for an equilateral triangle.
