Area of a Triangle and Polygon

Area of Triangles

It might be helpful to take notes in your math notebook!​

Fill in the Blanks

​To get the area of one triangle, you simply need to get half of the area of a rectangle!

​

The area of a rectangle is found by multiplying ​the base and height.

All rectangles are composed ​of two triangles as shown in the picture.

​

​The area of this rectangle is 4 x 8, which is 32 square units

​This means that one triangle is half of the rectangle, and half of 32 is 16 square units.

​

Multiple Choice

What is the area of this triangle? Go back to the previous slide if you don't know what to do!

• 12 square units

• 20 square units

• 15 square units

• 10 square units

Fill in the Blanks

Fill in the Blanks

Fill in the Blanks

Polygons are all shapes with 3 or more sides.

To get the area of a polygon, separate the shape into smaller parts to get the total area!​

The blue shape is an example of a polygon​

​

Area of Polygons

​The blue polygon can be separated into a rectangle and a triangle, as shown by the orange line above. You can then get the area of each and add them together!

Fill in the Blanks

Fill in the Blanks

Fill in the Blanks

Fill in the Blanks

Fill in the Blanks

Fill in the Blanks

Fill in the Blanks

Fill in the Blanks