Here we will learn about the graph of perimeter vs. length of the side of a square.
For a square we have, perimeter = (4 × side of
1. Consider the relation between the perimeter
and the side of a square, given by P = 4a.
Draw a graph of the above function.
2. From the graph, find the value of P. when
(a) a = 5
(b) a = 6.
1. The given function is P = 4a.
For different values of a, the corresponding values of P are given below.
On a graph paper,
plot the points O (0, 0), A (1, 4), B (2, 8), C (3, 12) and D (4, 16).
Join these points to get the required graph
line, shown below.
2. Reading off from the graph of perimeter vs. length of the side of a square:
(a) On the x-axis, take the point L at a = 5.
Draw LE ⊥ x-axis, meeting the graph at E.
Clearly, EL = 20 units.
Therefore, a = 5 ⇒ P = 20.
Thus, when a = 5, then P = 20.
(b) On the x-axis, take the point M at a = 6.
Draw MF ⊥ x-axis, meeting the graph at F.
Clearly, MF = 24 units.
Therefore, a = 6 ⇒ P = 24.
Thus, when a = 6, then P = 24.