Help with this math problem?

Question

This is some circle problem that i have no clue how to do:

If line PQ is both a diameter of circle A and a radius of circle B, what is the value of the fraction:

Area of circle A / Area of circle B ?

Please give me an explanation as well if you could. Explanation may give you best answer. Thank you =)

Answer 1

ok all you need to do is look at the formulas

first, lets make x the radius of circle 1 (basicaly 2x is the diameter)
so the radius of circle a would be 2x

now the formula for area of circle is PiR^2

so first circle area is x^2PI, and the 2nd circle is 4x^2PI(because (2x)^2= 4x^2)

and now if you do x^2PI/4x^2Pi, you will get your answer

the first circle is 1/4th the area of the 2nd circle

THE ANSWER IS ------> 1/4 <------- OK?

ATTENTION: O YEA BTW, WHOEVER SAYS THE ANSWER is 1/2 IS NOT RIGHT (i just got some instincts in this, bet someones going to say this)

Answer 2

PQ is both a diameter of circle A and a radius of circle B
:. Circle A is the inner circle of circle B
that is the diameter of circle A is the radius of circle B.
Let x = radius of circle B
:. radius of circle A = x/2

Area of circle A= Pi * r * r where r is the radius
Area of circle A = Pi * (x/2)^2

Area of circle B = Pi * (x)^2

:>Area of circle A / Area of circle B = Pi * (x/2)^2/ Pi * (x)^2
=1/4

Answer 3

call the lenght PQ "x" since the area of a circle is pi*radius^2. For circle A the area is pi*(x/2)^2 since x is the diamater, and 2r=d, this is equal to (pi*x^2)/4. As for circle B the area is pi*x^2 so the ratio of their areas is ((pi*x^2)/4)/(pi*x^2) wich cancels out to (1/4)/1 which is obviously equal to 1/4.

Answer 4

A radius is half of a Diameter Circle a has a diameter equal to the radius of circle b. A radius is half of a diameter, wich makes the area of circle b twice that of circle a so the fraction will equal 1/2

Answer 5

PQ=diameter of A
means, area of A = pi*r*r = pi* d*d/4 (coz r=d/2)
Area of A = pi*PQ*PQ/4
now, area of B = pi*PQ*PQ (as PQ=radius of B)
area A/area B = 1/4 <-- thats the answer

Answer 6

Area of A = π(PQ/2)^2
Area of B = π(PQ)^2
Area of A / Area of B = π(PQ/2)^2 / π(PQ)^2
Area of A / Area of B = (1/4)(π/π)(PQ/2)^2/(PQ)^2
Area of A / Area of B = 1/4

Answer 7

im to smart for math. 1+1=5 see!