Question 318758
1. Correct.
2. Correct.
3. Incorrect, I'm assuming a half-piece is one slice cut in half? 
{{{A=(100*pi)/32=9.8}}}
4. You mean 16 half-pieces or 32 half-pieces?
{{{A(16)=16*((100*pi)/32)=50*pi}}}
{{{A(32)=32*((100*pi)/32)=100*pi}}}
5. What is the radius of a circle where the area is (1/2) the original area.
{{{pi*R^2=50*pi}}}
{{{R^2=50}}}
{{{R=sqrt(50)}}}
{{{R=5sqrt(2)}}}
{{{R=7.07}}} inches
6. I'm not sure I understand the question. If you make a circumferential cut of the pizza at R=7.07, you will cut the area of the pizza in half. 
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The rectangle's area is,
{{{A=L*W=25*45=1125}}}
She needs to mow until there is 562.5 sq. ft. left.
Each cut takes (2+2=)4 feet off the width and 4 feet off the length of the rectangle to be mowed.
On her first cut, the area left to be mowed is reduced to,
{{{A=(L-4)*(W-4)=21*41=861}}}
On her second cut, the area left to be mowed is reduced to,
{{{A=(L-8)*(W-8)=17*37=629}}}
She then needs to cut another (629-562.5) sq.ft. or 66.5 sq.ft.
Since the mower is 2 ft. wide, she needs to move the mower another 66.5/2=33.25 ft off of the remaining 37x17 foot rectangle.
So 2 times around plus 33.25 feet would be exactly half.