1.

AB is a tangent to a circle with centre P and B is the point of contact. PA intersects the circle at C. If AB=15cm and AC = 9cm.Find the radius of the circle​

Answer»

Step-by-step explanation:

So this is how the FIGURE will look i hope much is clear from figure. This a abit rough sketch .

over here we already know why this is a right angle triangle as radius is perpendicular to the tangent at the point of contact .

Now,

(AB)^2 +( bp)^2 = (ap)^2

Note:- if u ever hv confusion in understanding the hypotenuse then remember that it will be the side opposite to 90°.

Now putting values,

(15)^2 + r^2 = ( 9 + r)^2

225 + r^2 = 81 + r^2 + 18r

r^2 gets CANCELLED ,

225-81 = 18r

144 /18 = r

8 = r

So the value of radius is 8 cm . Hope it was helpful.

You can even cross check by putting value of 8 in the pythogoras theorem,

both sides will come out to be 17 .



Discussion

No Comment Found

Related InterviewSolutions