You will need 90 feet of fencing to put all the way around a rectangular garden. The width of the garden is 10 feet. What is the length?

if it is a rectangle then the sides of the width would be the same. Also with the sides of the length. So add the widths, 10+10=20. Subtract 20 from 90, 90-20=70. Divide 70 by 2, 70÷2=35.  The length would be 35 feet.