If the diagonal and the area of a rectangle are 25 m2 and 168 m2, what is the length of the rectangle ?
A. 12 m
B. 17 m
C. 24 m
D. 31 m
Answer: Option C
Solution(By Examveda Team)
Let the length of the rectangle be x metres.Then, breath of the rectangle = $$\left( {\frac{{168}}{x}} \right)m$$
$$\eqalign{ & \therefore \sqrt {{x^2} + {{\left( {\frac{{168}}{x}} \right)}^2}} = 25 \cr & \Rightarrow \sqrt {{x^2} + \frac{{28224}}{{{x^2}}}} = 25 \cr & \Rightarrow {x^2} + \frac{{28224}}{{{x^2}}} = 625 \cr & \Rightarrow {x^4} - 625{x^2} + 28224 = 0 \cr & \Rightarrow {x^4} - 576{x^2} - 49{x^2} + 28224 = 0 \cr & \Rightarrow {x^2}\left( {{x^2} - 576} \right) - 49\left( {{x^2} - 576} \right) = 0 \cr & \Rightarrow \left( {{x^2} - 576} \right)\left( {{x^2} - 49} \right) = 0 \cr & \Rightarrow {x^2} = 576\,\,or\,\,{x^2} = 49 \cr & \Rightarrow x = 24\,\,\,or\,\,\,x = 7 \cr} $$
Hence, length = 24 m and breadth = 7 m
Related Questions on Area
A. 15360 m2
B. 153600 m2
C. 30720 m2
D. 307200 m2
E. None of these
A. 2%
B. 2.02%
C. 4%
D. 4.04%
E. None of these
A. 16 cm
B. 18 cm
C. 24 cm
D. Data inadequate
E. None of these
The percentage increase in the area of a rectangle, if each of its sides is increased by 20% is:
A. 40%
B. 42%
C. 44%
D. 46%
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