The area of a rectangle is equal to the area of a circle with circumference equal to 39.6 m. What is the length of the rectangle if its breadth is 4.5 metres?
(a) 33.52 m
(b) 21.63 m
(c) 31.77 m
(d) 27.72 m
(e) None of these
Solution: (d)
Circumference of the circle = 39.6 m
or, 2pr = 39.6 m
or, r = \(\displaystyle \frac{{39.6\times 7}}{{22\times 2}}=6.3m\)
Area of circle = \(\displaystyle \pi {{r}^{2}}=\frac{{22}}{7}\times 6.3\times 6.3=124.74{{m}^{2}}\)
Area of the rectangle =124.74
Length of the rectangle = \(\displaystyle \frac{{124.74}}{{4.5}}=27.72m\)
The perimeter of a square is one-fourth the perimeter of a rectangle. If the perimeter of the square is 44 cm and the length of the rectangle is 51 cm, what is the difference between the breadth of the rectangle and the side of the square?
(a) 30 cm
(b) 18 cm
(c) 26 cm
(d) 32 cm
(e) None of these
Solution: (c)
One side of square = \(\displaystyle \frac{{perimeter}}{4}=\frac{{44}}{4}=11cm\)
Perimeter of rectangle = \(\displaystyle 4\times perimeterofsquare=4\times 44=176cm\)
Width of rectangle = \(\displaystyle \frac{{perimeterofrec\tan gle}}{2}-length\)
\(\displaystyle \frac{{176}}{2}-51=88-51=37cm\)
Therefore, Required difference = width – side = 37 – 11 = 26 cm.
Inside a square plot, a circular garden is developed which exactly fits in the square plot and the diameter of the garden is equal to the side of the square plot which is 28 meters. What is the area of the space left out in the square plot after developing the garden?
(a) \(\displaystyle 98{{m}^{2}}\)
(b) \(\displaystyle 146{{m}^{2}}\)
(c) \(\displaystyle 84{{m}^{2}}\)
(d) \(\displaystyle 168{{m}^{2}}\)
(e) None of these
Solution: (d)
The area of the shaded region area of square – Area of the circle
Area of rectangular field is 3584 m square and the length and the breadth are in the ratio 7 : 2 respectively. What is the perimeter of the rectangle ?
(a) 246 m
(b) 292 m
(c) 286 m
(d) 288 m
(e) None of these
Solution: (d)
Area of field = \(\displaystyle 3584{{m}^{2}}\)
Let the length and breadth be 7x and 2x
Then \(\displaystyle 7x\times 2x\)= \(\displaystyle 3584{{m}^{2}}\)