Subject: Circle Geometry Problem Sat Sep 12, 2009 9:36 am
The radius of circle O is 12 inches and segment AB and CD are tangent to the circle at B and D respectively. AB= 16, and CD= 5 inches. What is OC + OA in inches?
AK_Kadaveru
Posts : 28 Join date : 2009-10-20
Subject: Re: Circle Geometry Problem Tue Oct 20, 2009 6:16 pm
OC + OA = 33 inches, I did it by using the pythogaras thereom. To find, OC, you do 52 + 122 = x2 (x= OC), which means OC = 13. To find OA, you do 162 + 122 = y2 (y= OA), and you get OA=20. so OC+OA = 13 + 20= 33 inches.
BhandarkarA
Posts : 85 Join date : 2009-09-11
Subject: Re: Circle Geometry Problem Tue Oct 20, 2009 7:12 pm
Correct. However, you could have done the latter application of Pythag. Theorem, 16^2 + 12^2 = y^2, faster using the primitive triple of 3-4-5.
Also, in your solution, remember to cite why exactly its a ninety degree angle where the segments AB and DC touch the circle. (Hint: it has to do with the relationship of a tangent line to a circle.)
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