Math 2b English
PREE
Raymond calculated the surface area of a cone that has a Analyze Raymond's work. Is he correct? If not, what
diameter measure of 8 meters and a slant height of 20.5 was his mistake?
meters. His work is shown below.
Yes, he is correct.
1. SA = 77(82) + (8)(20.5)
No; in step 1 he used the diameter measure instead
2. SA = 6411 + 16471
of the radius.
3. SA = 22871 m²
No; in step 2 he incorrectly evaluated the power to
64 instead of 16.
No; in step 3 he added the surface area and lateral
area incorrectly.
5) Intro