a farmer needs to buy fencing to go around his garden. The garden is a 20 by 15 rectangle . How much fencing will he need?

To calculate the amount of fencing needed for the garden, we need to find the perimeter of the rectangular garden. The perimeter is the total distance around the garden, which represents the length of fencing needed.

The given dimensions of the rectangle are 20 by 15, which means 20 units for the width and 15 units for the length.

To find the perimeter, we can use the formula:

Perimeter = 2 × (Length + Width)

Substituting the values, we get:

Perimeter = 2 × (20 + 15)
= 2 × 35
= 70 units

Therefore, the farmer will need 70 units of fencing to go around his garden.

Perimeter is 2L+2W=P

L=length
W=width
P=perimeter

Just plug it in.