Tag: [email protected] wrote: Someone submitted the form from your ‘Ask Your Questions Here’ page A user has submitted the contact form on your store. Here are their details: Email Address: [email protected]

Posted on by

Geometry Ch 3.1 #36

Questions: Help with Geometry ch.3.1 #36. We don’t understand how to get the last step in the answer. How does the 4 get under the “pie” and not also under the d square? Thanks

 

 

Answer from Dr. Callahan: 

Take these steps

 
A = pi*r^2
 
and 
 
r= d/2
 
 
Now substitute r from the second equation into the first to get
 
 
A = pi (d/2)^2 — so you are squaring both the d and the 2. 
 
 
to get
 
A = pi * d^2 / 4