To find the original length of the rope, we must find the length of rope used in the rectangle and in the circle, and add it to the length of rope that was leftover.
The length of rope used in the rectangle would be the perimeter of the rectangle, the perimeter of the rectangle is the sum of all his sides.
Perimeter of a rectangle = side + side + side + side
[tex]\text{Perimeter rectangle= 10+7+10+7=34 cm}[/tex]
The question gives us the perimeter of the circle, 20 cm this measure was the length of rope used in the circle.
[tex]\text{Perimeter circle= 20 cm}[/tex]
Now the total length of the rope was: The sum of the perimeters of both rectangle and circle and the length of rope that was left.
Total length rope = 34 + 20 + 10 = 64 cm