Geometry

Question Analysis:
This question tests recognition of equilateral triangle properties and how they relate to other triangle types.

Key Concept Explanation:
Equilateral triangles are also a special case of isosceles triangles (since at least two sides are equal).
The altitude of an equilateral triangle creates two right triangles.
Exterior angles follow the formula: Exterior Angle = 180° − Interior Angle

Step-by-Step Solution:
A) Correct – Every equilateral triangle is also an isosceles triangle (but not every isosceles triangle is equilateral).
B) Correct – The altitude divides an equilateral triangle into two 30-60-90 right triangles.
C) Incorrect – Equilate...