Mathematics for IGCSE & O level - Similarity (Section 1 - No. 26)
A building casts a shadow of 20 m at the same time as a 1 m ruler casts a shadow of 0.5 m. What is the height of the building?
10 m
20 m
40 m
50 m
解释
The scale factor is 20 / 0.5 = 40; height = 1 * 40 = 40 m