CIRCLES: TANGENTS
TWO CIRCLES CAN INTERSECT… in two points one point or no points
NO POINTS OF INTERSECTION (DIFFERENT CENTER)
NO POINTS OF INTERSECTION (SAME CENTER) Same center but different radii
1 POINT OF INTERSECTION (TANGENT CIRCLES) Internally Tangent Externally Tangent
2 POINTS OF INTERSECTION
COMMON TANGENTS Internal
COMMON TANGENTS External
If a line (segment or ray) is tangent to a circle, then it is perpendicular to the radius drawn to the point of tangency. Point of Tangency More Pythagorean Theorem type problems! Yeah!!
a 2 + b 2 = c 2 x = = x 2
a 2 + b 2 = c 2 RQ = (QR) 2 = (8+12) (QR) 2 = 20 2
r = (r + 16) 2 r = 10 r = r r = 32r
R S T If two segments from the same exterior point are tangent to a circle, then they are congruent. Party hat problems!
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