posted by Shar
A ladder 15m long reaches a window which is 9m above the groubd on one side of the street. Keeping its foor at the same point, the ladder is turned to the other side of the street to reach a window 12m high. The width of the street is ______ meter?
Remember your basic 3-4-5 right triangle. Scale it up by 3 and you have 9-12-15.
Now draw your diagram, and all should be clear.
Length of ladder=AC=15m
Height of window from ground
in first case AB=9m
ABC is right angled triangle
In second case
Let CE be length of ladder=15m
Height of window from ground=DE=12m
Triangle CDE is a right angled triangle
Width of street=BC+CD=9+12=21m