We now know that we can classify triangles by their angles. We can also classify triangles by their sides.

- scalene triangle-a triangle with no congruent sides
- isosceles triangle-a triangle with at least 2 congruent sides (i.e. 2 or 3 congruent sides)
- equilateral triangle-a triangle with exactly 3 congruent sides.
- NOTE:
- Congruent sides means that the sides have the same length or measure.
- We normally refer to a triangle with 2 congruent sides to be isosceles and a triangle with 3 congruent sides as being equilateral.
- HOWEVER, we can technically call an equilateral triangle (a triangle with 3 congruent sides) an isosceles triangle since it has at least 2 congruent sides. (Actually, it has more than 2 congruent sides---it has 3!) Personally, this is really a little stupid but it is something we just have to deal with in geometry.

Now you are ready to try a Sketchpad activity. You will have to think a little bit on this one and know a little bit about circles. TRY IT! You can figure it out!

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