Question
Calculate the area of a circle with a radius of 2 cm and a circle with a radius of 4 cm. Leave your answers in terms of pi.
When the radius doubles, does the area of the circle double?
A) 4π cm2; 8π cm2; NO
B) 4π cm2; 16π cm2; NO
C) 4π cm2; 16π cm2; YES
D) 4π cm2; 8π cm2; YES
c?
When the radius doubles, does the area of the circle double?
A) 4π cm2; 8π cm2; NO
B) 4π cm2; 16π cm2; NO
C) 4π cm2; 16π cm2; YES
D) 4π cm2; 8π cm2; YES
c?
Answers
Steve
Not C. doubling 4π gives 8π.
But D is also incorrect.
Note that replacing r with 2r means you have
π(2r)^2 = π*4r^2 = 4πr^2 not 2πr^2
But D is also incorrect.
Note that replacing r with 2r means you have
π(2r)^2 = π*4r^2 = 4πr^2 not 2πr^2
Ur MoM gAy PaPi LeZbO
no U!
luna
It is B. :)