Heron's formula · हीरोन का सूत्र

Three sides in, area out — with every step.

Heron's formula games

Side aSide b Side c

For a triangle with sides a, b, c: semi-perimeter s = (a + b + c) ÷ 2, and Area = √[s(s − a)(s − b)(s − c)]. No height needed.

Check first that any two sides add up to more than the third — otherwise there is no triangle.

For Class 9 (perimeter and area). Practice areas are whole numbers, checked by a program.

A one-page chart to stick on the wall, and a worksheet to practise.

s = (a + b + c) ÷ 2 · Area = √[s(s − a)(s − b)(s − c)]

kheloaurseekho.in — free charts, games and worksheets

Name: ____________________ Class: ______ Date: __________

1. Area of a triangle with sides 7, 24, 25 cm = ____

2. Area of an equilateral triangle of side 10 cm (use Heron) = ____

3. A triangular park has sides 50 m, 120 m, 130 m. Area = ____

kheloaurseekho.in — free charts, games and worksheets