Suraj0184
A wedding stage is a square of side 10 metres each. At a corner, a triangular section of the stage is cordoned off using a rope in a straight line. If the length of the rope is 6 metres, what is the maximum area (in square metres) which can be cordoned off in the triangle?
A. 9
B. 16
C. 25
D. 36
E. 49
Source : Wizako
Area of triangle is given as = 1/2 (l)*(b)
now, the area will have a maximum value if product of l, and b is maximum. Also from triangle inequality we know that sum of any two sides of triangle is always greater than the other.
so let two sides of triangle be x, and y so x+y>6
we also know that sqrt(x^2+ y^2) = 36
so that means no side of the triangle can be greater than 6. i.e x+y<11 so the possible value of x+y can be 7,8,9,10. Also, we know that product of two numbers is maximum when they are equal provided there sum is constant.
i.e. x = y
using this we have sqrt(2)x = 6
or x =3sqrt(2)
so Area = 1/2(3sqrt(2)*(3sqrt(2))
= 9
hence A