Find an equation for the perpendicular bisector of the line segment whose endpoints are ( − 1 , − 1 ) (−1,−1) and ( 9 , 7 ) (9,7)

Place the compass at one end of line segment.

Adjust the compass to slightly longer than half the line segment length.

Draw arcs above and below the line.

Keeping the same compass width, draw arcs from other end of line.

Place ruler where the arcs cross, and draw the line segment.

the answer is 31.27mph