China Naming Network - Almanac query - Li Ming wants to measure the height of a street lamp in the square from the ground. After dinner, the street lamp was turned on. He took a 2.8m-meter-long straight rod and tape measure and took Xiaojun to the road.
Li Ming wants to measure the height of a street lamp in the square from the ground. After dinner, the street lamp was turned on. He took a 2.8m-meter-long straight rod and tape measure and took Xiaojun to the road.
Answer: known: h 1=2.8m? L 1=3.5m？ L2 = 3.5m+7m = 10.5m；
Question: h2=?
Solution:
In sunlight, the height and shadow length of the object are as follows:
h 1=2.8m？
L 1=3.5m？ L2 =10.5m.
According to the similarity, the corresponding edge is proportional to: h1H2 = l1L2; Substitution value:
h2=L2L 1？ h 1 = 10.5m 3.5m×2.8m = 8.4m。
Answer: The height of the street lamp is 8.4 meters.