---
title: "Area of Triangles & Parallelograms"
description: "Calculate the area of parallelograms and triangles using formulae (A = b × h for parallelograms, A = ½ × b × h for triangles)"
canonical: https://lightmysky.com/learn/mathematics/area-of-triangles-and-parallelograms-mt_ML5t7n2-U8
source: https://lightmysky.com/learn/mathematics/area-of-triangles-and-parallelograms-mt_ML5t7n2-U8.md
retrieved: 2026-10-19
---

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# Area of Triangles & Parallelograms

Calculate the area of parallelograms and triangles using formulae (A = b × h for parallelograms, A = ½ × b × h for triangles)

Subject: Mathematics · Area: Measurement · Ages 10 to 11
Page: https://lightmysky.com/learn/mathematics/area-of-triangles-and-parallelograms-mt_ML5t7n2-U8

## Ready when they can

- Calculate the area of a parallelogram with base 8 cm and height 5 cm
- Calculate the area of a triangle with base 12 cm and height 7 cm
- Explain why the area of a triangle is half the area of a related parallelogram

## Lesson: Area of Triangles and Parallelograms

Area tells you how much flat space a shape covers. You measure it in square units, like square centimetres (cm²). For a parallelogram, the formula is simple: multiply the base by the height. A = b × h.

**Example.** A parallelogram has a base of 8 cm and a height of 5 cm. Multiply the base by the height: 8 × 5 = 40. The area is 40 cm².

A triangle is different. Two matching triangles fit together to make a parallelogram with the same base and height. So a triangle's area is always half of that parallelogram's area. The formula is A = ½ × b × h.

*(drawing: This triangle has a base of 12 cm and a height of 7 cm. Half of 12 × 7 is 42, so its area is 42 cm².)*

**Tip.** Always multiply base by height first. Only halve the answer if you are working with a triangle. Keep the units as square centimetres (cm²).

**Recap.** Multiply base by height for a parallelogram; halve that answer for a triangle.

## Practice

18 questions on this page, each with its working shown.

## Needs first

- [Multiplying fractions (age 10+)](https://lightmysky.com/learn/mathematics/multiplying-fractions-age-10-mt_AabJisinfi)
- [Area and perimeter of rectangles](https://lightmysky.com/learn/mathematics/area-and-perimeter-of-rectangles-mt_eiB3-6pu6a)
- [Using Simple Formulae](https://lightmysky.com/learn/mathematics/using-simple-formulae-mt_Jvg8X0N5u0)
- [Classifying shapes by properties](https://lightmysky.com/learn/mathematics/classifying-shapes-by-properties-mt_liIW336odh)

## Opens up

- [Surface Area of Solids](https://lightmysky.com/learn/mathematics/surface-area-of-solids-mt_hdhmurUndc)
- [Area and volume formulae](https://lightmysky.com/learn/mathematics/area-and-volume-formulae-mt_tAJH5BrpOx)