A street light is mounted on top of a 20-ft-tall pole and a 5-ft-tall woman wail from the pole at 6 ft/sec. What is the rate of change of the length of her shadow when she is 15 ft from the pole? decreasing at a rate of 3 ft/sec increasing at a rate of 3 ft/sec increasing at a rate of 2 ft/sec O decreasing at a rate of 2 ft/sec