Acircular wire of diameter 77 cm is bent in the form of a rectangle whose length is 142% of its breadth. What is the area of the rectangle? (Take $$\pi = \frac{22}{7}$$)
let breadth of rectangle be b cm.
Then, length=142%of b=142b/100
diameter of circle= 77cm,
radius of circle,r =77/2 cm.
perimeter of rectangle = circumference of circle
$$\rightarrow2( length + breadth)=2\pi r$$
$$\rightarrow 2(\dfrac{142b}{100}+b) = 2\times\dfrac{22}{7}\times \dfrac{77}{2})$$
$$\rightarrow 2\times \dfrac{100b+142b}{100}=11\times22$$
$$\rightarrow \dfrac{242b}{100}=\dfrac{242}{2}$$
$$\rightarrow 242b=121\times100$$
$$\rightarrow b=\dfrac{12100}{242}$$
$$\rightarrow b=50cm$$
$$\rightarrow area of rectangle = length \times breadth$$
$$\rightarrow area of rectangle =\dfrac{142b}{100}\times b$$
$$\rightarrow area of rectangle =\dfrac{142\times50}{100}\times50$$
$$\rightarrow area of rectangle =3550cm^2$$
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