Areas of Quadrilaterals Jessica Shim Investigations in Geometry
Review Can you name these quadrilaterals? Click on the shapes to find out the answers.
Area of a rectangle Watch this video for an explanation of how to find the area of a rectangle
Area of a square Using the information you know about finding the area of a rectangle, can you find the area of a square?
Area of a square The area of the square is base x height, just like the area of a rectangle. However, we know all of the sides are the same. So… Area of a square = side 2
You try it! What are the areas of the following quadrilaterals? Click on the shapes for the answers. 5 in 3 in 6 in
Area of a parallelogram The area of a parallelogram is base x height, where the height is perpendicular to the base. Area = base x height Why do you think the height is perpendicular to the base? Think of the area of a rectangle… height base
Area of a parallelogram You can create a rectangle by cutting a parallelogram into two (down the height) and connecting the triangular piece to the other side… height base height base …which is why the area is base x height
Area of a trapezoid Watch this video for an explanation of how to find the area of a trapezoid
You try it! What are the areas of the following quadrilaterals? Click on the shapes for the answers. 5 in 6 in 3 in 4 in 3 in
BONUS! How about a triangle? The area of a triangle is Area =½ (base x height) Why? Hint: think about the area of a rectangle
BONUS! How about a triangle? It’s because a triangle can be made by cutting a rectangle in half!
You try it! What is the areas of the following triangle? Click on the shapes for the answers. 5 in 4 in
Links Used You’re done! Click on the “done” button to exit. Done
Parallelogram GO BACK
Trapezoid GO BACK
Rectangle GO BACK
Square GO BACK
5 in x 3 in = 15 in 2 GO BACK 5 in 3 in
(6 in) 2 = 6 in x 6 in = 36 in 2 GO BACK 6 in
5 in x 3 in = 15 in 2 GO BACK 5 in 3 in
[(4 + 6) / 2 ] x 3 = (10 / 2) x 3 = 5 x 3 = 15 in 2 GO BACK 6 in 4 in 3 in
(4 x 5) / 2 = 20 / 2 = 10 in 2 GO BACK 5 in 4 in