Triangles ABC and DBC are right angled triangles with common hypotenuse BC , BD and AC intersect at P when produced . If P of BD, PA = 8 cm, PC = 4 cm and PD = 3.2 cm , then the length of BD, in cm is :
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 6.8
ΔABP andΔDCP are similar
PA/PD = PB/PC
PA × PC = PB × PD
8 × 4 = 3.2 × PB
32 = 3.2 × PB
32/3.2 = PB
PB = 10
BD = PB - PD = 10 - 3.2 = 6.8