# math

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Need help.....
A child of height 1.2 metres stands 3 metres from the foot of a lamp post of height 2.8 metres, at the top of which there is a small source which can be considered as a point. What is the length of the shadow cast by the child upon the ground?

• math -

make a sketch
let the length of the child's shadow be x m
from the similar triangles....

1.2/x = 2.8/(x+3)
2.8x = 1.2x + 3.6
1.6x = 3.6
x = 2.25

• math -

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