Mr. Hansen
Geom. HW due 2/26/09

Remaining Problems from §10.9

§10.9 #9bc
9.(b)
	Given: is equilateral; arc AB is centered at O Find: Length of arc AB
	Since , length of arc AB = . Answer: , or approx. 18.8
	[Reasonableness check: Since all sides of are 18, AB = 18. Since the shortest distance between A and B is a straight segment, arc AB must be a little bit longer than 18.]
(c)
	Given: is equilateral; arc AB is centered at O Find: Length of arc AB
	Since AB = 18, the arc is a semicircle having r = 9. Answer: , or approx. 28.3.