## ML Aggarwal Class 6 Solutions for ICSE Maths Chapter 9 Algebra Ex 9.2

Question 1.

If the side of an equilateral triangle is l, then express the perimeter of the triangle in terms of l.

Solution:

Perimeter (P) of the equilateral triangle with side l = Sum of the lengths of sides of the equilateral triangle = l + l + l = 3l

Question 2.

The side of a regular hexagon is l. Express its perimeter in terms of l.

Solution:

Perimeter (P) of the regular hexagon with side l = Sum of the lengths of all sides of the regular hexagon

= l + l + l + l + l + l = 6l

Question 3.

The length of an edge of a cube isl. Find the formula for the sum of lengths of all the edges of the cube.

Solution:

Total length (L) of the edges of a cube = Sum of the lengths of all (12) edges of the cube.

= l + l + l + l + l+ l + l + l + l + l + l + l = 12l

Question 4.

If the radius of a circle is r units, then express the length of a diameter of the circle in terms of r.

Solution:

Draw a circle

Let AB is a diameter of the circle

C its centre

AB = AC + CB

⇒ d = r + r

⇒ d= 2r