Intro to Perimeter and Area

We use measurement to understand sizes and amounts of things, and we define the units with which we measure these things. For example, if a builder has house plans, each part of the house is drawn with lengths, widths, and heights specified in feet and inches for every boundary the house and  for the floor space. The dimensions of the land on which the house is set is also measured..

from houseplans.com

from houseplans.com

When we measure the dimensions of buildings, parcels of land, containers, and other objects and shapes, we need to know what is meant by the terms that are used.

The perimeter of a shape is the total length of the boundary of the shape on a flat surface. 

The area of a shape is the total number of square units needed to cover the shape on a flat surface.

Select and copy everything below this line. You can paste it in either the Textbox Entry on this page OR in a Word document. You will then answer the questions and show your work begining on the line below each part of each problem.

1-1 Below is a red rectangle that has a rectangular hole in its interior. For example, it could be an office building with a courtyard in the middle.

a. If the hole in the middle of the red rectangle has a length of 4 units and a width of 2 units, what are the length and width of the outside of the red rectangle? 

b. The length all the way around the outside of a shape on a flat surface is called the perimeter. What is the perimeter of the red rectangle ?

c. What are the length and width of the white space inside the red rectangle?

d. What is the perimeter of the white space inside the red rectangle?

e. If the area of the white space in the rectangle is 8 square units, what is the area of the red part of the rectangle?

1-2 We will use some electronic tools from College Preparatory Mathematics (CPM) in this course to explore concepts like perimeter and area. Click on this CPM Perimeter and Area Links to an external site. link and refer back to the directions on this page. 

The name of the webpage is CPM Tiles. Please play around on this page for a few minutes so you can figure out how it works. Click on the ? icon and go to page 14 in the Help document to read the instructions for the Perimeter and Area tools. After you play around in CPM Tiles, here is your assignment in CPM Tiles:

Click on the Background menu and click Grid to create a grid background.

Create a shape of your choice on the background. 

Click on the General Tools icon and create textboxes to label the lengths and widths of your shape. Create textboxes to label the total length around your shape (the perimeter) and the number of square units (the area) your shape has.

When you have created your shape and labeled its dimensions, its perimeter, and its area, click the paper and pen icon in the top left corner of the page. Click the Save Option. This will bring up a link. Copy (Click Ctrl and C at the same time) the URL, return to this page and Paste (Click Ctrl and V at the same time) the URL below this line.

Click Submit Assignment.