# Other : MAT/116 Week 3 dq 1

In week 3, Section 2.4 of the text

discussed some mathematical formulas that are used in various

fields to solve

problems in geometry.

Heres a problem involving the

circumference and radius of a circle.

The equation for

circumference

Cin terms of radius

ris:

C = 2

p

r.

Lets assume the earth is a perfect

sphere and we tie a rope around the earth. The rope sits

tightly on the surface

(circumference) of the earth.

Now lets cut the rope and add 1

foot to it. (Weve added 1 foot to the circumference.) The

rope no longer sits

tightly on the earth, but is now some distance away from the

surface.

Question: How far away from the

surface is the rope after weve added the foot to the

circumference? Or asking

another way– when I add 1 foot to the circumference, what

happens to the

radius? Show the equations and how they were used to solve

this

problem.

( Note: No need to bring in the

distance around the earth which is 25000 miles. Just work

with the equation for

circumference.)