PrepWisePrepWiseArea of Rectangles & Triangles
Geometry & MeasuresKey Facts

The Key Formulas

Part of Area of Rectangles & Triangles — GCSE Mathematics

This key facts covers The Key Formulas within Area of Rectangles & Triangles for GCSE Mathematics. Revise Area of Rectangles & Triangles in Geometry & Measures for GCSE Mathematics with 12 exam-style questions and 6 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 2 of 7 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 2 of 7

Practice

12 questions

Recall

6 flashcards

The Key Formulas

Shape Formula Remember
Rectangle Area = length × width A = l × w
Square Area = side × side A = s²
Triangle Area = ½ × base × height A = ½bh

Important: For triangles, the HEIGHT must be PERPENDICULAR (at 90°) to the base!

Keep building this topic

Read this section alongside the surrounding pages in Area of Rectangles & Triangles. That gives you the full topic sequence instead of a single isolated revision point.

What is Area?Why is Triangle Area = ½ × Rectangle?Worked Example 1: RectangleWorked Example 2: Triangle

Practice Questions for Area of Rectangles & Triangles

Which formula gives the area of a rectangle with length l and width w?

  • A. 2(l + w)
  • B. l + w
  • C. l × w
  • D. (1/2) × l × w
1 markfoundation

Explain why the area formula for a triangle uses the perpendicular height rather than the slant height.

2 markshigher

Quick Recall Flashcards

Rectangle Area
Area = length × width (A = l × w)
Triangle Area
Area = ½ × base × perpendicular height (A = ½bh)

Want to test your knowledge?

PrepWise has 12 exam-style questions and 6 flashcards for Area of Rectangles & Triangles — with adaptive difficulty and instant feedback.

Join Alpha

Previous

What is Area?

Next

Why is Triangle Area = ½ × Rectangle?