If the scale factor between two circles is 7a/9b what is the ratio of their areas? a. 49a/81bb. 49a2/81b2 c. 81b2/49a2d. 81b/49a

we know that

the ratio of their areas is equal to the scale factor squared

so

ratio of their areas=scale factor²> [7a/9b]²> 49a²/81b²

therefore

the answer is the option

49a2/81b2

the answer is d

step-by-step explanation:

ca = ec

cpctc makes it so that corresponding parts of the triangle you proved to be equal are equal, the other options aren't part of the part of the triangles you proved to be equal.