Answers for the problems at the end of Wednesday's class

Side of a triangle are 6, 11 and 8.

Scalene because all different.

6^2 + 8^2 = 100 < 11^2 = 121, so it is obtuse.

Area = 15sqrt(39)/4

Points are (2, 1) (5, 5) and (8, 9)

(2, 1) - (2, 1) = (0, 0)
(5, 5) - (2, 1) = (3, 4)
(8, 9) - (2, 1) = (6, 8)

Area =  ½| 3x8 - 6x4 | = 0

The three points are colinear.