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Re: Geometry help please!!!
1) I'm assuming that point A is on the circle. Placing the corner of the page at the origin puts the center of the circle at (r,r) and point A at (2,1). The distance from the center to point A is r.
r = Sqr((r-2)2+(r-1)2)
r2 = (r-2)2+(r-1)2
r2 = (r2-4r+4)+(r2-2r-1)
0 = r2 - 6r + 5
0 = (r - 5)(r - 1)
r = 5 or r = 1
2) See diagram.
(R - r)2 + R2 = (R + r)2
(R2 - 2Rr + r2) + R2 = R2 + 2Rr + r2
2R2 - 2Rr + r2 = R2 + 2Rr + r2
R2 - 2Rr = 2Rr
R - 2r = 2r
R = 4r
3) See diagram.
a2 + d2 = 42 = 16
a2 + b2 = 32 = 9
b2 + c2 = 22 = 4
c2 + d2 = DP2
a2 + d2 = 16
a2 + b2 = 9
d2 - b2 = 7
c2 + d2 = DP2
b2 + c2 = 4
d2 - b2 = DP2 - 4
DP2 - 4 = 7
DP2 = 11
DP = Sqr(11)
Edit: I mixed up the files - Q2.jpg is for #3, and Q3.jpg is for #2
Re: Geometry help please!!!
oh....dang, I should have used graphs....
But thanks anyway Logico ^-^!