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**1. Homework Statement**

A man 6 feet tall walks at a rate of 5 feet per second away from a light that is attached to a pole 15 feet above the ground. At what rate is the length of his shadow changing when he is 30 feet from the base of the pole?

I get that this is really like a two similar triangle problem, the way the light is shining and the shadow cast by the man

so i called the larger triangle ∆abc

and the smaller ∆xyz

The larger is the one that is caused by the light

a (x value) = 30 feet (Distance from Light Pole) + Shadow Length

b (y value) = 15 feet (Light Pole)

c (z value) = the Pythagorean value

The smaller triangle

x (x value) = Shadow Length

y (y value) = 6 feet (Man's Height)

z (z value) = the Pythagorean Value

Now i have figured out some values.

a = 30 feet

b = 15 feet

y = 6 feet

c

^{2}= (30

^{2}+ (b - y)

^{2})

c = √981

**2. Homework Equations**

I assume a

^{2}+ b

^{2}= c

^{2}

since it's a right triangle

but i don't have enough values

**3. The Attempt at a Solution**

i don't really have one. Sorry if that was confusing. I can try and clarify if need be.