MGMAT Foundations of Math II: Translate Words - Geometry

[mjnar1]

Hello,

Can someone help me understand the answer to question #4?

What is the area of the largest circle that can be drawn on an 8 inch by 10 inch sheet of paper?

A. 4pi inch^2
B. 5pi inch^2
C. 16pi inch^2 (answer)
D. 25pi inch^2
E. 64pi inch^2

If there is an 8X10 square, the diameter of a circle within that square would equal 8, 1/2 of 8 is 4. The formula for Area=R*pi^2, shouldn't the answer be 4pi inch^2 or 16pi, without the exponent?

[cyber_office]

Hi,

I think that is just convention to express area in terms of squared units. I don't think they are stating that you need to further square 16 Pie. All they are saying is that the convention for expressing area is to use the term "Squared". For example, let's say you have a square with side 7. When you calculate the area, you use the formula, A = S^2. In this case, the area of the square is 49. However, when you express it in units of measurements, you would state that the area of the square is 49 square centimeters or 49 square miles or whatever the unit of measurement of the side of the square was.

Hope that helps.

CY

[mjnar1]

ok, thank you! that makes sense now. i thought the answer was being expressed in A=R^2pi form.

[Ben Ku]

If there is an 8X10 square, the diameter of a circle within that square would equal 8, 1/2 of 8 is 4. The formula for Area=R*pi^2 [this is incorrect], shouldn't the answer be 4pi inch^2 or 16pi, without the exponent?

The area of a circle is Area = pi * (r ^2), in this case Area = pi * (4^2) = pi * 16 = 16pi. Because we're talking about an area, the units are inch^2.

Hope that makes sense.

[imanemekouar]

I don t get it the hall problem.can you please in a different way showing the relation you used for each step. tks so much

[RonPurewal]

I don t get it the hall problem.can you please in a different way showing the relation you used for each step. tks so much

do you understand what the problem is asking you to do?

to find the biggest circle that can fit on a piece of paper, you should just think about the biggest possible diameter.
if the diameter stretches all the way across the paper, then it will be 8 inches.
that would mean the radius is 4 inches.
therefore, the area is pi(4^2), or 16pi square inches.