# Isosceles Trapezoid: Angles and Diagonals

- Author:
- L Sliver, Tim Brzezinski

**Students:**The applet below contains a quadrilateral that

**ALWAYS remains an ISOSCELES TRAPEZOID.**Be sure to move the

**BIG BLUE VERTICES**of this

**ISOSCELES TRAPEZOID**around as you answer each investigation question!

## Base Angles

Measure the base angles using the measuring tool, then manipulate the applet to make different isosceles trapezoids. 1. What can you conclude about the measure of the base angles of the isosceles trapezoid? 2. What can you conclude about the opposite angles of the isosceles trapezoid? 3. What can you conclude about the consecutive angles along a leg of the isosceles trapezoid? 4. Does you conclusions apply to any trapezoid (not isosceles)?

## Diagonals

Using the measuring tool, measure the length of the diagonals. Manipulate the applet to make different isosceles trapezoids. 1. What can you conclude about the diagonals?