If x is the length of a median of an equilateral triangle, then its area is :
A. x2
B. $$\frac{1}{2}{x^2}$$
C. $$\frac{{\sqrt 3 }}{2}{x^2}$$
D. $$\frac{{\sqrt 3 }}{3}{x^2}$$
Answer: Option D
Solution(By Examveda Team)
Let the side of the triangle be aThen,
$$\eqalign{ & {a^2} = {\left( {\frac{a}{2}} \right)^2} + {x^2} \cr & \Leftrightarrow \frac{{3{a^2}}}{4} = {x^2} \cr & \Leftrightarrow {a^2} = \frac{{4{x^2}}}{3} \cr} $$
∴ Area :
$$\eqalign{ & = \frac{{\sqrt 3 }}{4}{a^2} \cr & = \frac{{\sqrt 3 }}{4} \times \frac{{4{x^2}}}{3} \cr & = \frac{{{x^2}}}{{\sqrt 3 }} \cr & = \frac{{\sqrt 3 {x^2}}}{3} \cr} $$
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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