Math Homework, HELP!?!?

O.k, I'm doing my math homework and I have no idea really what I am doing here! We are finding the Area and Circumference in angles.


Here are the math problems:


Pie (the pie symbol) = 3.14





Radius=7cm


Area=?


Circumference=?





Radius=21 m


A(area)=?


C(Circumference)=?





Diameter=20 km


A=?


C=?





Radius=5m


A=?


C=?





Radius=42km


A=?


C=?





Radius=11m


A=?


C=?





Diameter=78cm


A=?


C=?





Diameter=6.4cm


A=?


C=?





Diameter=12mm


A=?


C=?





Radius=5 cm


A=?


C=?





Radius=14m


A=?


C=?





Diameter=12.6m


A=?


C=?





Radius=3m


A=?


C=?





Radius=100m


A=?


C=?





A means Area


and C means


Circumference

Math Homework, HELP!?!?
I'll help you with circumference. I won't use a problem above. I'll make one up.





R = 9


Pi is 3.14. You need to times the radius x2. 9 x 2 = 18. So the circumference is 18. Now take 18 and times that by pi.





1 3


3.14


x 18


-------------


25.12


+ 31.40


--------------


56.52





The circumference is 56.52.





And it's pi not pie.
Reply:radius is half the diameter..its comon sense
Reply:i suggest you study and not sleep in class. Your embarrassing yourself in front of us.
Reply:Area- {Pie}R[squared]





Circumference- Diameter [multiply] {Pie}
Reply:I could better answer your questions in the "Live Chat" section of this website:





http://mathhelpfast.weebly.com/





I am the creator of the site and would be more than happy to help you out!





Thanks
Reply:Simple, all you need to know are these formulas.





Circumference = pi times diameter





Area= radius squared times pi





Radius also is half the circumference.





One more thing, squared means you multiply that number by itself. So 3 squared is 3 x3 which equals 9.





Good luck!
Reply:I think this would help. You could use the formulas such as for area: pie r squared and for circumferance: 2pie r.


So for the first one, the area is pie 7 squared and the circumerance would be 2pie times 7.
Reply:I would advise you to review your notes and textbook. They should contain this information.





The radius is the distance from the center of the circle to any point on the edge.





The diameter is twice the radius, being the distance across the circle at the widest point.





The constant pi is defined as the ratio of a circle's circumference to its diameter. (pi=C/d)





The area of a circle is equal to pi*(radius)^2.





With a few manipulations of the equations, that should be plenty of information for you to complete your homework. As I said, it's probably also available in your textbook.
Reply:http://www.ilc.org/cfmx/AAT/AATChat/inde...





real teachers help you on your homework.
Reply:i don't know i hate math!!
Reply:Look, if your seriously sitting down and doing your homework, you need to re think your life. Math homework is a scam, its a waste of time and doesnt get you anywhere. Just write down some numbers on the paper, then tomorrow in class turn it in and tell the teacher you didnt understand it and you need help. Im sure your teacher will help you. Or you could play it the easy way and not do your homework at all. I find that much more fun.
Reply:These are all the same problem. BTW, it's pi (not pie).





All you need to know for these is the diameter D = 2r, the area A = pi * r^2, and the circumference C = 2*pi*r.





So, for the first one, radius r = 7cm.


So the area A = pi * (7cm)^2


= 49*pi cm^2


(This is the exact answer. If your teacher wants a numeric approximation, use a calculator. 49*pi is about 153.93)





The circumference C = 2 * pi * 7 cm


= 14 * pi cm





2) radius r = 21 m


A = pi * (21m)^2


= 441 * pi m^2





C = 2 * pi * 21 m


= 42 pi m





They're really all exactly the same. Just watch out for the ones that give you the diameter:





3) D = 2r = 20 km


r = D/2 = 10 km


A = 100 pi km^2


C = 20 pi km





Is that enough to go on?
Reply:Ya um good lucky with that
Reply:im not going to answer all those questions for you, but i'll tell you the formulas





radius=half the diameter


diameter=2x raduis


circumference=radius squared x pie





i hope that helped, good luck:D
Reply:A=pie*r^2


C=2*pie*r
Reply:i could tell you the answer.. but that wont do you any good on your test, will it?
Reply:to find area





you square the radius and multiply it by pi





to find circumference you multiply pi by 2 and then multiply it by the radius