Given: The perimeter of a rectangle is $130\ cm$. The breadth of the rectangle is $30\ cm$. To do: To find the length and the area of the rectangle. Solution: As given, the perimeter of the rectangle $P=130\ cm$ The breadth of the rectangle $b=30\ cm$ Let "$l$" be the length of the rectangle. We know that, $P=2(l+b)$ $\Rightarrow 130\ cm=2(l+30\ cm)$ $\Rightarrow 130\ cm=2l+60\ cm$ $\Rightarrow 2l=130-60$ $\Rightarrow 2l=70$ $\Rightarrow l=\frac{70}{2}$ $\Rightarrow l=35\ cm$ So, the area of the rectangle $A=l\times b$ $=35\ cm\times 30\ cm$ $=1050\ cm^2$ Therefore, the length of the rectangle is $35\ cm$, and the area of the rectangle is $1050\ cm^2$.
Solution: Breadth of the rectangle = 30 cm Perimeter of a rectangle = 130 cm Perimeter of rectangle = 2 × [Length(l) + Breadth(b)] 130 cm = 2 × (l + 30 cm) 130 cm = 2l + 60 cm 2l = 130 cm - 60 cm 2l = 70 cm l = 70/2 cm l = 35 cm Area of Rectangle = Length × Breadth = (35 × 30) cm2 = 1050 cm2 ☛ Check: NCERT Solutions Class 7 Maths Chapter 11 Video Solution: Class 7 Maths NCERT Solutions Chapter 11 Exercise 11.1 Question 7 Summary: The perimeter of a rectangle is 130 cm. If the breadth of the rectangle is 30 cm, its length is 35 cm. Also, the area of the rectangle is 1050 cm2. ☛ Related Questions: Math worksheets and |