# Related rates

A spotlight on the ground shines on a wall 12 m away. If a man 2 m tall walks from the spotlight toward the building at a speed of 1.6 m/s, how fast is the length of his shadow on the building decreasing when he is 4 m from the building?

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#### Solution Preview

We assume x shows the distance between the man and the building. Also let's ...

#### Solution Summary

This shows how to find the rate of change of the length of a shadow on a building.

$2.19