A triangular corner is cut from a rectangular piece of paper and the resulting pentagon has sides 5, 6, 8, 9, 12 in some order. The ratio of the area of the pentagon to the area of the rectangle is -
(A) 11/18
(B) 13/18
(C) 15/18
(D) 17/18
Correct option (D) 17/18
Explanation:
Clearly x = 4 = 12 – 8
& y = 3
area of rectangle = 12 x 9 = 108
∴ area of pentagon = 12 x 9 – area of Δ
= 108 – 1/2 x 3 x 4 = 102
∴ ar(rectangle)/ar(pentagon) = 102/108 = 17/18
