Question

The length of line segment AK is 640 meters. ∆ABC, ∆CDF, and ∆FJK are similar, and 2AC = CF = 2FK. The first pillar is 20 meters tall. What is the area of ∆CDF

Answer 1

A to K = 640 meters

2AC = CF = 2FK


2AC = 2(160) = 320
CF = 320
2FK = 2(160) = 320

AC = 160
CF = 320
FK = 160
AK    640

BG = 20 m ; Area = (160m*20m) / 2 = 3,200/2 = 1,600 m²

20:160 = x : 320
20*320 = 160x
6,400 = 160x
6,400/160 = x
40 = x

Area of CDF = (320m*40m) / 2 = 12,800 / 2 = 6,400 m²