SOLUTION: A building 60 feet tall casts a shadow 20 feet long. A person 6 feet tall is walking directly away from the building toward the edge of the building's shadow. How far from the buil

Algebra ->  Equations -> SOLUTION: A building 60 feet tall casts a shadow 20 feet long. A person 6 feet tall is walking directly away from the building toward the edge of the building's shadow. How far from the buil      Log On


   

Question 982336: A building 60 feet tall casts a shadow 20 feet long. A person 6 feet tall is walking directly away from the building toward the edge of the building's shadow. How far from the building will the person be when the person's shadow just begins to emerge from that of the building?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
You have a similar triangle situation.
Big triangle, 60 high, 20 along the bottom;
Small triangle, 6 high, ball along the bottom value, b.



The hypotenuse represents the shadow boundary from the 60 foot building extending on the ground the 20=x+b feet. Point H represents the head of the six-foot tall person.

Question asks for some x value such that x+b=20; the x is the distance along the ground from the base of the building to where the person's feet will be when his head just touches the edge of the building's shadow.

These equations would be formed and can be solved as you need:
system%2820%2F60=6%2Fb%2Cx%2Bb=20%29
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