Question

3. In the figure below, E is on AD and C is on BD. The dimensions given are in meters. What is the length, in meters, of CD?

Answer 1

Answer:

C. 3,960

Step-by-step explanation:

∆ADB ~ ∆EDC. Therefore,

$\frac{AB}{EC} = \frac{DB}{DC}$

$\frac{2,000}{1,200} = \frac{2,640 + x}{x}$ (substitution)

Solve for x

$\frac{5}{3} = \frac{2,640 + x}{x}$

Cross multiply

$5*x = 3(2,640 + x)$

$5x = 7,920 + 3x$

5x - 3x = 7,920

2x = 7,920

x = 7,920/2

x = 3,960 meters