## 35-36 Time Rates: Lengthening of shadow and movement of its tip in 3D space

**Problem 35**

An arc light hangs at the height of 30 ft above the center of a street 60 ft wide. A man 6 ft tall walks along the sidewalk at the rate of 4 ft/sec. How fast is his shadow lengthening when he is 40 ft up the street?