Big Idea – We can describe, measure, and compare spatial relationships. to build on students' knowledge of triangle and to develop students' reasoning with properties of triangle to develop students' ...

To calculate the area of a rectangle you multiply the length by the width. A right-angled triangle is like half a rectangle. So to calculate the area of a triangle, you can work out the area of the ...

The area of the rectangle is 8 cm 2. Two triangles make the rectangle. The area of one triangle is half the area of the rectangle. \(8 \div 2 = 4~\text{cm}^2\) The area of a triangle can also be ...