Surface area of a sphere is 4 times Pi times r^2.
In other words, 4 of the largest circles from cross-sections of a sphere would cover the sphere completely.
But a hemisphere has a base, so its surface is 3 times Pi times r^2.
HW #14: p 457: 1-6, and p 544:8,9,12-14. Show work and use of formulas.
On B day we practiced degrees, radians, & coordinates for a point on the unit circle.
Warm-up was p 532: 1 & 8.
We checked homework and showed lots of work as the homework was fairly difficult (HW #13).
I took a grade on HW #12 & #13 - 4 pts each.
Then we took the Unit Circle Quiz - 24 pts and worked on the new homework for the rest of class.
Attached: answers to HW #13 from the board.