Finding the Area

HOMEWORK

Area of a Parallelogram

The images to the right are called parallelograms. A parallelogram is any shape with two sets of parallel sides (it often looks like a squishy square or rectangle).

1. Either print or trace the images to the right onto a separate piece of paper.

2. Take each parallelogram and cut it along the dotted line. (You should now have a triangle and a funny looking quadrilateral be careful not to cut any of the numbers).

3. Take the triangle and see if you can place it somewhere next to the quadrilateral to make a shape you are VERY familiar with.

4. Glue the new shape onto a blank piece of paper.

5. If you remember how from last year, find the area of this new shape you have created (again, this is a shape you know well!)

6. Write a rule for finding the area of any parallelogram.

Area of a Triangle

You will want to use the formula you found for area of a parallelogram to solve this.

1. Draw a triangle on a piece of paper and cut it out (make sure it is big enough for you to work with). Now cut out another triangle that looks EXACTLY THE SAME! (I'd trace the first one and cut it out if I was you).

2. Can you put the two triangles together to form a very familiar shape? Glue the shape you formed in your math notebook.

3. Look at your new shapes. Based on what you know about area so far, describe how you would find the area of ONE of these triangles.

Repeat steps 1-3 for at least ONE other triangle.

4. Write a general rule for how to find the area of a triangle.

Area of a Trapezoid

A Trapezoid is a shape with only one set of parallel sides. Those parallel sides are always different lengths.

1. Look at the trapezoids to the right. The dotted lines are showing you that if you have two trapezoids that are exactly the same, they can be put together to form a parallelogram made up of the solid trapezoid and the dotted line trapezoid.

2. Look at all the trapezoids to the right. How could you find the length of one side of the parallelogram (this is the solid trapezoid plus the dotted figure)? Write a general rule for how to find this length.

3. Do your best to write a general rule for how to find the Area of a Trapezoid.

YOU DO NOT ACTUALLY NEED TO SOLVE ANY OF THESE PROBLEMS WITH NUMBERS. YOU ARE JUST TRYING TO WRITE GENERAL RULES. WE WILL SOLVE THEM IN CLASS.

CLASSWORK

Make sure you save these pages, do a few of each type of problem. You will be finishing the problems you didn't do today another day in class.

Parallelogram

Go Math Pg. 373 #1-13

Go math Pg. 374 ALL

Practice Book P183 All

Triangle

Go Math Pg. 377 #1-10

Go Math Pg. 381 #1-7

Practice Book P185

Practice Book P187

Trapezoid

Go Math Pg. 385 #1-10

Go Math Pg. 389 #1-7

Practice Book P189

Practice Book P191

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