Arectangle lot 30m by 20m is surronded on all four sides by a concrete walk 3m wide. if you need to concrete only the sidewalk, how much concrete will you need? (surface area)

The length of the rectangle is 30 m

The width of the rectangle is 20 m

The sidewalk is 3m wide on all sides, so

length of sidewalk = 30+6 =36 m

Width of sidewalk = 20+6 = 26 m

Area of rectangle =

Area of rectangle =

Area of rectangle including sidewalk =

Hence, area of sidewalk alone = area of rectangle with sidewalk -  area of rectangle

Surface Area = m²

(-5,-28)

i graphed to on desmos.