QUESTION 3
Easy
Suppose the length of a rectangle is 13cm. Find the area if the breadth is i) 12cm, ii) 10cm, iii) 8cm. Find the linear pattern representing the area of the rectangle.
SOLUTION
1
Recall area of rectangle formula
Area = length × breadth
Given length \(= 13\) cm
Given length \(= 13\) cm
2
Calculate area for each breadth
i) breadth \(= 12\) cm
Area = \( 13 × 12 = 156 cm^2\)
ii) breadth \(= 10\) cm
Area = \( 13 × 10 = 130 cm^2\)
iii) breadth \(= 8\) cm
Area = \( 13 × 8 = 104 cm^2\)
Area = \( 13 × 12 = 156 cm^2\)
ii) breadth \(= 10\) cm
Area = \( 13 × 10 = 130 cm^2\)
iii) breadth \(= 8\) cm
Area = \( 13 × 8 = 104 cm^2\)
3
Find the linear pattern
Here, breadth is the variable. Let breadth \( = b\) cm
\(Area = 13 × b = 13b\)
This is the linear expression in \(b\).
\(Area = 13 × b = 13b\)
This is the linear expression in \(b\).
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Final Answer :
Area for each breadth: \((i)156, (ii)130, (iii)104\)
Linear expression: \(13b\)
Concept Note
If one quantity = constant × another quantity, it is a linear expression.
\(Area = fixed \) \(length × breadth\)