The minute hand of a clock is 4.5 inches long. What distance does the tip move in 45 minutes?
The minute hand of a clock, while moving, creates an arc that is some part of a circle.
Since the minute hand is only moving for 45 minutes, it moves 3/4 of an entire circle.
This circle would have radius of 4.5 inches.
The circumference of a circle is πd, where d is 2r.
We can substitute 2*4.5 for d.
The circumference of a circle with radius of 4.5 is 9π.
Since only 3/4 of the entire circumference is travelled, multiply 9π by 3/4.
(3/4)*9π=27π/4, or ≈21.206