第,一条;;
It is given that the scale of a map is 1:250000.It the length of a railway line on the map is 121cm ,find its actual length in km
第二条;;
the figure shows a scale drawing of a pyramid.
(a)Express the scale in the fram 1 cm:n mm
(B) If the height of the pyramid in the drawing is2.5cm,
what is its actual hight?
第三条;;
The scale of a map is 1:20000.If the lrgth and the width of rectangular park on the map are 4.5cm and 2.8cm respectively,find the actual area of the park in km2.