Investigating Mathematics with GeoGebra

Henrico County Public Schools

What are the angle relationships?

READ the instructions on the right and INTERACT with the GeoGebra applet below.
Click on the reset icon icon to reset the diagram.

Sorry, the GeoGebra Applet could not be started. Please install Java 1.4 (or later) to use this page.

Investigation Steps

 Step 1 Close 
  1. Why is line segment BC considered a transversal?

  2. What is the measure of ∠ACB ?
    Hint: What is the sum of the angles of a triangle?

  3. What is the measure of ∠BCE ? What is the measure of ∠x + ∠y ?
    Hint: What are supplementary angles?
 Step 2 Close 
  1. Why are ∠BAC and ∠y are congruent?

  2. Why are ∠ABC and ∠x are congruent?

 Questions Close 
    Submit your written response to the following questions to your instructor.

  1. As you move points A, B, and C. What changes?

  2. What remains the same? Explain.