Area and Perimeter: Mowing the Lawn

Date: 6/1/96 at 20:52:59
From: Anonymous
Subject: Area and Perimeter Word Problem

Jenn and Gregg have both agreed to mow half of a lawn. This lawn is a 
rectangle, 25 feet by 45 feet. Their lawn mower cuts a 2 feet wide 
path. If Jenn starts at a corner and makes a path around the outside,
how many times should she go around to cut one half of the lawn?

I started by multiplying 25 and 45 and got 1125. The next thing I 
did was to divide 1125 by 2 to get an answer of 564.1. I do not know 
if that's right and the answer does not make any sense!!

Date: 6/2/96 at 8:0:36
From: Doctor Anthony
Subject:Area and Perimeter Word Problem

The total area is 25 x 45 = 1125.  Half the area is 562.5  

The area cut during the first circuit will be: 
(25 x 45 - 21 x 41) = 264 square feet

During the second circuit, the area cut will be:
(21 x 41 - 17 x 37) = 232 

The total area cut so far is 264 + 232 = 496. The area that Jenn still 
has to cut is 562.5 - 496 = 66.5 sq.ft. If we do a complete third 
circuit, the area cut would be (17 x 37 - 13 x 33) = 200. So Jenn has             
66.5/200 = .3325 (approx 1/3) of the third circuit to make.

Jenn does 2 + (1/3) circuits to cut half the lawn.

-Doctor Anthony,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/