Explain how to calculate the area of a triangle

Maths

In this unit pupils will explain how to calculate the area of a parallelogram and a triangle describing the relationship between scale factors and side lengths. They will describe positions in all four quadrants drawing and translating simple shapes and reflecting them in the axes In the future unit pupils extend their knowledge of plotting coordinates by now plotting non-integer values.

In the prior unit pupils used knowledge of shape properties to draw, sketch and identify shapes. In this unit pupils will explain how to calculate the area of a parallelogram and a triangle. They will describe the relationship between scale factors and side lengths of two shapes. They will describe positions in all 4 quadrants drawing and translating simple shapes and reflecting them in the axes.

Area, perimeter, position and direction

Which of the dotted lines shows the perpendicular height of the triangle?

Multiply the base by the perpendicular height. 

Multiply the base by the perpendicular height and halve it. 

Multiply the base by the perpendicular height and double it.

How do you calculate the area of a triangle?

Area = base × perpendicular height ÷ 2 

Area = perpendicular height × base ÷ 2 

Which of these show the correct formula for calculating the area of a triangle? 

Calculate the area of the triangle. {{  }} cm².

Calculate the area of a triangle with a base of 14 cm and a perpendicular height of 9 cm. {{  }} cm².

Exactly the same shape but smaller or bigger.

How many of the side lengths are the same in a scalene triangle?

How do you calculate the area of a rectangle?

How do you calculate the area of a parallelogram?

This lesson will soon be taken down.

Explain how to calculate the area of a triangle

Lesson outcome