Question

What are the perimeters of triangle, trapezium, parellelogram, rhombus, circle, square, cube, cuboid and rectangle​

Answer 1

Step-by-step explanation:

Let us see the formula to find the perimeter of figures one by one.

Perimeter of Triangle:

Perimeter of triangle is calculated by adding all three sides of the triangle. In other words,

⇒ Perimeter of triangle = a + b + c

There is a special case for finding the perimeter of equilateral triangle. We know that, all three sides of an equilateral triangle are equal.

⇒ P(Equilateral triangle) = a+b+c

⇒ P(Equilateral triangle) = a+a+a ---[a = b = c]

⇒ P(Equilateral triangle) = 3a (or) 3b (or) 3c

(a, b and c are considered as three sides of a triangle.)

Perimeter of trapezium:

Perimeter of trapezium is calculated by adding two bases and two legs of the trapezium(four sides).

⇒ Perimeter of Trapezium = a+b+c+d

(a, b, c and d represents four sides of the trapezium.)

Perimeter of parallelogram:

Perimeter of parallelogram is also equal to sum of its four sides.

Perimeter of Rhombus:

Let the side of rhombus be a. We know that all the four sides of rhombus are equal.

⇒ P(Rhombus) = a+a+a+a

⇒ P(Rhombus) = 4a

Perimeter of circle:

Perimeter of circle is also called as circumference of circle. The formula is:

⇒ Perimeter of circle = $2 \pi r$

Perimeter of square:

⇒ Perimeter of square = 4×Side

This formula is same as perimeter of rhombus. It is because, squar's four sides are equal as that of rhombus.

Perimeter of cube:

⇒ Perimeter of Cube = 12×Side

Perimeter of cuboid:

⇒ Perimeter of cuboid = 4(l+b+h)

Perimeter of rectangle:

Let's add all the sides of rectangle to find its perimeter:

⇒ Perimeter of rectangle = l+l+b+b

⇒ Perimeter of rectangle = 2l+2b

⇒ Perimeter of rectangle = 2(l+b)