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Isosceles Triangles

Author:Rett McBride
An isosceles triangle is has exactly two sides of equal length. (An equilateral triangle as three sides of equal length.

Triangle ABC is a dynamic isosceles triangle.

Question 1:

Re-position the vertices several times. Which sides of triangle ABC always have equal length? (Select two)

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

Lengths of sides

Question 2

Position the vertices so that they have integer coordinates. Confirm your answer to Question 1 by calculating the lengths of the two sides that you selected. Are they in fact the same? Hint: the distance formula follows. You can check your answers by clicking on the "Show lengths of sides" box in the applet.

This formula is closely related to a well-known and often used theorem. Can you say identify that theorem?
This formula is closely related to a well-known and often used theorem. Can you say identify that theorem?

Question 3:

The measure of angle ACB is given. What is the measure of angle CAB? Angle ABC?

Bonus Question: The measure of angle ACB is given. The length of side CB is given. Can you solve the triangle without using the distance formula?

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