Question 17.
In a rectangle ABCD, AB = 9 cm and BC = 6 cm. P and Q are two points on BC such that the areas of the figures ABP, APQ, and AQCD are in geometric progression. If the area of the figure AQCD is four times the area of triangle ABP, then BP : PQ : QC is
Question Explanation
It is given that AB = 9 cm, BC = 6 cm.
It is also known that the areas of the figures ABP, APQ, and AQCD are in geometric progression.
Hence, the area of the ABP, APQ, and AQCD are k, 2k, and 4k respectively.
The ratio of BP, PQ, QC will be the ratio of the respective triangles. Hence, we can draw a line from point A to point C.
Let the area of triangle AQC be x, which implies the area of triangle ADC = ADQC - AQC = 4k -x, which is equal to the sum of the area of triangle APB, AQP, and ACQ, respectively.
Therefore, 4k-x = 3k+x
=> x = k/2
Hence the ratio of BP: PQ: CQ = k:2k: k/2 =2:4:1
