how do I work out pi maths questions say for instance... If a circle has a radius of 3.7, what is the diameter?

Question

anonymous · Answer

7.4

shubhamsrg · Answer

pi is just another constant,,like 2,3,10,,etc..its no big deal..

anonymous · Answer

Yeah but Im not sure how to get the answer can you explain it to me pls

callisto · Answer

diameter = 2 times radius

callisto · Answer

Circumference of circle = 2 pi r , where pi is the constant and r is the radius of the circle

anonymous · Answer

d = 2r
where d is the diametre and r is the radius.

callisto · Answer

Area of the circle = pi r^2 , where  pi is the constant and r is the radius of the circle

anonymous · Answer

Can anyone tell me how to work out the answer on a calculator pls

anonymous · Answer

jst multiply 3.7*2 and u'll get the answer.

anonymous · Answer

@Bridgette, @Callisto and @kajolc.2496  gave you the equation. Since the diameter is two times the radius, just multiply the radius by two.

anonymous · Answer

Thank you very much I have just started learning pi at school and teacher isnt explaining it very well and it is confusing me, im just not getting the pi questions.
Is there any other information you could give me to help me understand working out pi questions.

anonymous · Answer

yaa there are many
area of a circle, circumference , diametere,etc

anonymous · Answer

area = pi*r*r
circumference = 2*pi*r
diametre = 2r

anonymous · Answer

Circumference means the length of the outside of a circle. Think of it this way. Make a circle with a piece of string. The length of that string is the length of the circumference.

The diameter is the longest line that can fit inside the circle. It always bisects it (cuts it in two).

The radius is a straight line from the center point to the outside edge.

The diameter is twice the length of the radius.

The circumference can be found by taking twice the length of the radius and multiplying by pi. Same thing as the diameter times pi.

The area of the circle is the radius squared, and then times pi.

anonymous · Answer

ok so question.... If a circle has a diameter of 5, what is the radius? 
r = _____ the answer the wld be 2.5 is this right?

anonymous · Answer

That is correct.

anonymous · Answer

If a a circle has radius 7, what is the area?
 A = _____ wld the answer to this be 153.93804

anonymous · Answer

Yes, that is correct.

anonymous · Answer

Thank you so so much you have been a wonderful help I am understanding better now.

anonymous · Answer

Not a problem at all!