1. Polygon Areas 2 The area of a parallelogram and a triangle Tandi Clausen-May Click the mouse

2. Click the mouse only when you see or If you click too soon you will miss the best bits. Click the mouse Click to see Click the mouse

3. The area of a parallelogram Click the mouse

4. We know that Area of a rectangle = base × height Click the mouse = length of a row × number of rows base height

5. We can shear the rectangle into a parallelogram. Click to see the rectangle shear Area of the rectangle = base × height parallelogram Area of the rectangle base height Click the mouse

6. A triangle is half of a rectangle. We can shear the rectangle into a parallelogram. Click to see the rectangle shear We have sheared the triangle too! Click the mouse

7. Let’s shear some more triangles. Click to see the triangle shear Click the mouse

8. Click to see these triangles shear The triangles are all different shapes, but they all have the same area. They have the same area as this one. Click the mouse

9. base height base × height 2 Area = They are all half the base times the height Click the mouse

10. Click to see the triangle shear Summary base height Area = base × height Click the mouse 2

11. The End Tandi Clausen-May