Construction #8
Tangent line to a circle at a point ON the circle
Tangent line to a circle at a point ON the circle
To see a video of Mr. Ochs doing examples
Mr Ochs Video To see and example done in flash click on a link below Math Open Ref |
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Construct the tangent line to a circle at a point ON the circle.
1) With a straight edge draw a ray, from the center of the circle, passing through the given point A that is on the circle.
2) Put the pointer on point A and measure to point P (the center) then move the compass around and strike an arc on the ray outside the circle with the same distance as AP make this point Q
(you don't have to measure from point A to P in this step, any radius would be fine, I just think measuring to P is easier to remember)
3) Construct the perpendicular bisector of segment PQ.
(the perpendicular bisector should be tangent to the circle P at point A)
1) With a straight edge draw a ray, from the center of the circle, passing through the given point A that is on the circle.
2) Put the pointer on point A and measure to point P (the center) then move the compass around and strike an arc on the ray outside the circle with the same distance as AP make this point Q
(you don't have to measure from point A to P in this step, any radius would be fine, I just think measuring to P is easier to remember)
3) Construct the perpendicular bisector of segment PQ.
(the perpendicular bisector should be tangent to the circle P at point A)