## 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