subject: Calculating Perimeters [print this page] Introduction Introduction
Sum of all the edges of the regular or irregular geometric shaped objects forms the perimeter of the object and the surface occupied by the object inside the edges is called as area of the object. We have formulas to calculate the perimeter of geometric shapes like square, rectangle, parallelogram, trapezium, circle etc...This article helps us in calculating the perimeter of the given shapes.
Formulas Used for Calculating Perimeters of Various Geometrical Shapes:
Square: A square has four equal sides.
Perimeter of a square = a + a + a + a = 4a units where a is the side of the square
Rectangle: A rectangle has equal opposite sides. We call the two dimensions of the rectangle as length and width.
Perimeter of a rectangle = l + w + l + w = 2(l + w) units where l is the length of the rectangle and w is the width of the rectangle
Circle: It is a plane round figure with center. A circle is usually described with it's radius. Distance between the center of the circle and a point on the circumference of the circle is radius and two times the radius is called as diameter of the circle.
Circumference of a circle = 2 r units where r is the radius of a circle
= 3.14 (constant)
Triangle: A triangle has three sides.
Perimeter of a triangle = (a + b + c) units where a, b and c are sides of the triangle.
These are the formula for calculating perimeters .
Problems on Calculating Perimeters:
Ex 1: Find out the perimeter of a square having a side of 4 cm?
