ratio of areas

Question

 a radius of 6 in. and circle B with a radius of 12 in- find the ratios of areas

Answer 1

Area = pi*r2

 

Where r is the radius of the circle.  So the ratio of the areas of two circles (A and B) with radii r_A and r_B is:

 

Area_A              pi*r_A²

-----------  =   ----------- = (r_A/r_B)² = (6/12)² = (1/2)² = 1/4

Area_B              pi*r_B²