Learn how to calculate the areas of rectangle, triangle, and circle in Excel for a single cell or range of cells usin this formula.

For a right-angled triangle, follow these steps to calculate the length of a side, x, when another side and an angle Ɵ is given: Label the two sides that contain information in the diagram with ...

Revise how to calculate the area of a triangle. Learn how to calculate the triangle's area by first finding the area of a rectangle in this BBC Bitesize maths guide.

The same calculation applies no matter how many lines there are. Compare that approach to brute-force counting, which is not only laborious and error-prone but provides no way to check the answer.