Area of Triangles and Parallelograms — Interactive Lesson (Year 6)

Why is a triangle’s area half the base times height? This 38-slide interactive lesson builds the area of triangles and parallelograms from a rectangle pupils already know.

Mastering the Area of Triangles and Parallelograms in Year 6 Maths

Pupils use their previous knowledge of finding the area of a rectangle to find the area of a right-angled triangle, then extend this to any triangle, before using the same idea for a parallelogram. They see that a rectangle contains two triangles, so the area of a triangle is base × height ÷ 2, or ½BH, and that any side can be used as the base once the height is measured from the opposite vertex. For a parallelogram, they learn area = base × height, for example a base of 12 cm and height of 6 cm giving 72 cm².

What’s Included

• 38-slide interactive lesson on the area of triangles and parallelograms
• Learning objectives building from the area of a rectangle
• Worked examples for right-angled and other triangles
• Worked examples for parallelograms with base and height
• Reasoning and problem-solving questions with instant feedback

Key Benefits for Students

• Builds both formulae from something pupils already know
• Shows that any side of a triangle can be the base
• Links triangles and parallelograms in one lesson
• Instant feedback on answer questions

Why Teachers Love It

• No prep — ready for whole-class teaching on an interactive whiteboard
• A long, structured lesson that can be split across sessions
• Self-marking questions support independent practice
• Suits teaching, revision and homework
• A dependable foundation before KS3 area work

Love this? You’ll love…

• Area of Any Triangle — Interactive Lesson (Ages 10–11)
• Calculating Volume of Cubes and Cuboids — Interactive Lesson (Ages 10–11)
• Comparing Volumes — Interactive Lesson (Ages 10–11)

A dependable addition to a Year 6 geometry topic, giving pupils a secure link between the shapes they already know and new area formulae. Confidence here supports circles, compound shapes and volume at secondary school.

Build confident area skills today — Add to Basket.

FAQs

What year group is this for?
Year 6 (ages 10–11), KS2.

Does it cover parallelograms as well as triangles?
Yes — both shapes are covered.

Is it self-marking?
Yes, with instant feedback on the questions.