Consider the two similar right triangles formed. One has perpendicular sides 15 and 40 +x. The other has corresponding perpendicular sides 6 and x. The shadow length is x.
15/(40+x) = 6/x
(40+x)/x = 15/6 = 2.5
40/x + 1 = 2.5
40/x = 1.5
x = 26.67 feet
A streetlight is mounted on top of a 15 ft. pole. A 6-ft tal man walks away from the pole along straight path. How long is his shadow when he is 40 ft from the pole?
4 answers
did you make a sketch?
Let the length of his shadow be x
I have 2 similar triangles, so use a proportion:
6/x = 15/(x+40)
cross-multiply
15x = 6x + 240
9x = 240
x = 240/9 = 80/3 ft or 26 2/3 ft
Let the length of his shadow be x
I have 2 similar triangles, so use a proportion:
6/x = 15/(x+40)
cross-multiply
15x = 6x + 240
9x = 240
x = 240/9 = 80/3 ft or 26 2/3 ft
How tall is a tree that casts a 50 foot shadow at the same time a 18 foot street light casts a shadow of 18 feet?
Find the total surface area of a refrigerator box that is 4 feet wide, 6 feet high, and 4 feet deep. The total surface area is