1. has travelled a horizontal distance of 2400 metres.
8. Dalculate to 2 significant figures the altitude of the plane (height of the plane above
a. Draw a sketch to represent the information given.
the ground after 25 seconds).
A plane takes off at an angle of elevation of 17° to the ground. After 25 seconds, the plane

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.