The point lies outside the circle with centre and radius . Find the length of a tangent from to the circle.
Answer and explanation
Correct answer: A.
- Step 1: The distance from to the centre is .
- Step 2: Tangent length .
Answer
.
Why not the others: is what you get if you give the distance from to the centre. is what you get if you subtract the radius from the distance. is what you get if you forget the square root.
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