## Monday, 3 June 2019

### Unit 11 - Area of triangles and parallelograms

Hello, hello!
As we're learning about the properties of polygons, we need to know what the area of a polygon is.

### Area

The area of a polygon is the quantity that expresses the extent of a shape. It is two-dimensional and is normally calculated by multiplying the length and the height of the shape. The typical shape of rooms and other spaces are not just a rectangle or a square, so we'll need to add the areas of the shapes that compose them:

Other problem we may have is when the area we want to measure is a shape within another shape:

In this case, we need to subtract the area of the outside rectangle minus the area of the small one, in order to know the difference between them.

#### Area of a paralellogram

Paralellograms are always measured as if they were rectangles: #### Area of a triangle

The area of a triangle is (height × width) ÷ 2. #### Area of a Regular Polygon

The area of a Regular Polygon is the Perimeter x apothem / 2. Here you have some games to practice on perimeters and areas:

I hope you found these useful!
Bye, bye, butterflies!