# ﻿Estimating Areas

Warmup

Activity #1

Estimate Area (Practice exercise) .

Take a Quiz. Answer the following questions to demonstrate your ability in estimating area. • Attempt the question before adding a grid in the background. When you find the area, remove the grid before you click “Next” for a new shape.

Activity #2

Estimate the Area of a circle by Counting Enclosed Squares. • The diameter of the circle below is 10 units. Estimate its area.
• Use the slider to change the diameter to five different values and estimate the area.

Activity #3

Estimate Area of a Complex Shape.

Here is a floor plan of a house. Approximate lengths of the walls are given. • Study it and answer the question that follows.

What is the approximate area of the home, including the balcony? Explain or show your reasoning.

Challenge #1

Find the area of the polygon. Show your reasoning.

Challenge #2

The two triangles are equilateral, and the three pink regions are identical. The blue equilateral triangle has the same area as the three pink regions taken together.

What is the ratio of the sides of the two equilateral triangles?

Challenge #3

The radius of Earth is approximately 6,400 km. The equator is the circle around Earth dividing it into the northern and southern hemispheres. (The center of the earth is also the center of the equator.) What is the length of the equator? Quiz Time