Mathematics 7

# Surf for More Math

## Lesson 4 - Area of a Trapezoid

Use these interactive activities to encourage your child to have fun on the Web while learning about the area of a trapezoid.

### Goal

Develop and apply the formula for the a area of trapezoid.

### Builds Upon

Student Book pages 162-165

### Instructions for Use

Touch Pegs prompts your child to investigate how length and width relate to area.

To use Touch Pegs, select a blue band under "Bands" then drag it to any location on the grid. Release the band to anchor it. A red node appears at the top of the band. Click on any part of the band and drag it in any direction. It will stretch like a rubber band. Release the band to secure it to a point on the grid. Secure the band to other points on the grid to form a trapezoid.

To change a vertex of the trapezoid, release a node by holding down the "Ctrl" key and clicking the node. To colour the area inside the trapezoid, click on the trapezoid and then click one of the colour buttons to the left of the grid.

Calculate the area of the trapezoid you created. Click the "Measure" button to check your answer. Click on the "Clear" button to start the exercise over again.

Trapezoid Perimeter and Area helps your child understand the formula for the area of a trapezoid.

To use Trapezoid Perimeter and Area, drag the pink dots to change the dimensions of the trapezoid. Notice the changes in perimeter and area as the dimensions change. The area of the trapezoid is the sum of the area of two triangles formed by the trapezoid diagonal.

Calculating the Area of a Trapezoid helps your child practice applying a formula for the area of a trapezoid.

To use Calculating the Area of a Trapezoid, click the "Start" button. Based on the measurements given, input the area of the trapezoid in the text box. Click the "Check" button to check the answer.