Answer:
20 feet tall
Step-by-step explanation:
If these are at the same angle, which i'm assuming they are, the following would happen:
Put length of 1 item over its shadows length equal to 2nd items length over its shadow. Put x in the place you want to find (Lamp in this case)
(3/1.8)=(x/12)
Cross multiply
36=1.8x
Divide by 1.8 on both sides
20=x
