How to express perimeter of a given figure using algebraic expressions?
We know that perimeter is the sum of the length of all sides of a closed figure. In other words, it is the length of the boundary of the figure.
We will now express the perimeters of some closed figures as algebraic expressions.
| Figure | Perimeter | Perimeter as Algebraic Expression
(Length of side = ‘l’) |
| Equilateral triangle | 3 x length of side | 3𝑙 |
| Square | 4 x length of side | 4𝑙 |
| Regular Pentagon | 5 x length of side | 5𝑙 |
How to express area of a given figure using algebraic expressions?
Area is the total region or space enclosed by a closed figure in 2 dimensions.
| Figure | Area | Area as Algebraic Expression (length = ‘l’, breadth = ‘b’, base = ‘b’, height = ‘h’) |
| Square | (𝑙𝑒𝑛𝑔𝑡ℎ 𝑜𝑓 𝑠𝑖𝑑𝑒)2 | 𝑙2 |
| Rectangle | length x breadth | 𝑙𝑏 |
| Triangle | ½ x base x height | 1
𝑏ℎ 2 |