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The Side Story (Equilateral, Isosceles, Scalene)

Every triangle has a story to tell, and the first clue is the length of its sides. Based on their sides, triangles can be sorted into three main families.Your mission is to use the applet to build one of each!
  • Equilateral: The "all equal" triangle. Your goal is to make all three sides have the same length.
  • Isosceles: The "two of a kind" triangle. Your challenge is to make exactly two sides equal, while the third side is different.
  • Scalene: The "no match" triangle. In this one, all three sides must have different lengths.
Drag the vertices AB, and C until you successfully create each type. Pay close attention to the side length measurements as you work.

When you successfully created a perfect equilateral triangle, what did you notice about its three angles?

Was it easier to make a scalene triangle or an isosceles triangle? Why do you think that is?

A triangle with side lengths of 7 cm, 9 cm, and 11 cm is called...

Select all that apply
  • A
  • B
  • C
  • D
Check my answer (3)

If a triangle is equilateral, which of the following MUST be true?

Select all that apply
  • A
  • B
  • C
  • D
Check my answer (3)