Hi all! I was reading the following article on howstuffworks.com: http://science.howstuffworks.com/question379.htm It says to apply the following procedure to estimate the building height: 1. Measure the length of the broomstick's shadow 2. Calculate the ratio of the broomstick's shadow length to the broomstick's height 3. Measure the tower's shadow 4. Apply the ratio to discover the tower's height. Attached is a picture I drew showing why this simple calculation seems confusing to me. The black box represents the stick placed beside the building (white box). If the rays of the suns strike the ground at different angles, then how can a similar triangle approach using just ratios of the lengths be used to calculate the building height? Is my drawing wrong? Have I assumed something wrong by drawing the sun as a point of light?