Question

If the line segment Q is tangent to the circle, find Q. (circle below)
A. 5
B. sqrt21
C. sqrt30
D. sqrt70
E. none of these

Answer 1

@Coolsector

Answer 2

so usually what we do :

Answer 3

okay so what steps should i take on this one?

Answer 4

now cos(a) = 3/q
and also (in the big triangle) cos(a) = q/10
so we have
3/q = q/10
q^2 = 30

Answer 5

i assumed that the center of the circle really lies on the long black line

Answer 6

so the correct choice would be C in this case? that's the answer i'm getting as well.

Answer 7

(the long black line perpendicular to the q line)

Answer 8

yes, C.