Geometry

Question Analysis:
This question tests the ability to differentiate between isosceles and equilateral triangles.
The main focus is on recognizing that isosceles triangles have at least two equal sides, but not necessarily three.

Key Concept Explanation:
An isosceles triangle has at least two equal sides, meaning it can have two but not necessarily three equal sides.
If a triangle has three equal sides, it is an equilateral triangle, not necessarily isosceles.

Step-by-Step Solution:
A) True. By definition, an isosceles triangle always has at least two equal sides.
B) True. The angles opposite the two equal sides are always equal.
C) False. If all three sides are equal, the triangle is equilateral, which is a special case of an isosceles triangle but not a requirement.
D) True. In an isosceles triangle, the altitude from the vertex always bisects the base.
Since we need to find the statement that is NOT...