From point A 10cm from a plane P, a perpendicular line AC is drawn passing through a circle with canter C and radius of 8 cm in the plane. At any point B on this circle, a tangent BD is drawn 18cm in length. FInd the distance from A to D.

---- i need the illustration

Question

From point A 10cm from a plane P, a perpendicular line AC is drawn passing through a circle with canter C and radius of 8 cm in the plane. At any point B on this circle, a tangent BD is drawn 18cm in length. FInd the distance from A to D.

----> i need the illustration

anonymous · Answer

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anonymous · Answer

how can i solve this one?

anonymous · Answer

well, you'll need to find CD. to do that, note that BDC is a right angle triangle.

anonymous · Answer

how does it became a right triangle?

anonymous · Answer

CB and BD are given. so this calls for pythagoras theorem.
Then also note that ADC is also a right angle triangle. 
AC is given, CD is found.

anonymous · Answer

Well, since it is a tangent, tangents always meet the circle at right angles.

anonymous · Answer

|dw:1353476601742:dw|

so the answer for AD is 22.1 cm??

anonymous · Answer

yh. lol you've got it!

anonymous · Answer

thanks :))

anonymous · Answer

you're welcome :)