How Much Corresponding Base Must be Decreased? If
Answer: (2) 100/11%
Let be the height of a triangle is = h and base is b.
Then, the area of the triangle = bh/2
let be the base is decrease by X%.
According to the question,
bh/2 = ( b – b x X/100) (h + h x 10/100)/2
bh = (100b – bX)(11h)/100 x 10
1000 x bh = 1100bh – 11bhX
1000bh – 1100bh = – 11bhX
– 100bh = – 11bhX
X = 100/11%
Hence, the answer is (2) 100/11%.