ML Aggarwal CBSE Solutions Class 6 Math 12th Chapter Algebra Exercise 12.2
(1) If the side of an equilateral triangle is l, then express the perimeter of the triangle in terms of l.
Solution: In equilateral triangle all the sides are equal.
There are 3 sides in a triangle
One side of the triangle = l
Then, the perimeter of the triangle = 3 x l = 3l
(2) The side of a regular hexagon is l. Express its perimeter in terms of l.
Solution: In regular hexagon there are total 6 sides and all the sides are equal.
One side of regular hexagon here is l.
So the perimeter of a regular hexagon = 6 x l = 6l
(3) The length of an edge of a cube is l. Find the formula for the sum of lengths of all the edges of the cube.
Solution: There are total of 12 edges in an cube.
Here, the length of an edge of a cube is l.
Then, the sum of lengths of all the edges of the cube = 12 x l = 12l
(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: Here the radius of a circle is r units.
Then the length of a diameter of the circle in terms of r units = 2 x r = 2r
Answer: 2r units