Here's the question you clicked on:
eroshea
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
how can i solve this one?
well, you'll need to find CD. to do that, note that BDC is a right angle triangle.
how does it became a right triangle?
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.
Well, since it is a tangent, tangents always meet the circle at right angles.
|dw:1353476601742:dw| so the answer for AD is 22.1 cm??
yh. lol you've got it!