Math Focus 7

# Surf for More Math

## CHAPTER 5: MEASUREMENT

### Lesson 1: The Area of a Parallelogram

Use these interactive activities to encourage students to have fun on the Web while learning about measurement. Students can try these activities on their own or in pairs.

Goal

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

Builds Upon

Student book pages 194–199

Instructions for Use

Area of a Paralellogram allows students to discover how they can use the formula for area of a rectangle to find the area of a parallelogram.

Read the “Instructions” section and then the “Exploration” section. Try creating several different rectangles from the parallelogram. Make sure you find out what measurements of the parallelogram you need in order to find its area.

Area of a Paralellogram--Calculations allows students to manipulate the size of a parallelogram and discover how that changes the area.

Drag the orange dots on the vertices to move and resize the parallelogram. As the size of the parallelogram changes, the area will be recalculated.

Also try estimating the area of some parallelograms by clicking on “hide details.” Then, drag the orange dots on the vertices to make a random-sized parallelogram. Now estimate the area of the parallelogram just by looking at the squares inside it.