Sir how i solve this question of class 10th of exercise 10.2 of ncert math of question no.6, give me the best and simple way to solve this question The length of a tangent from a point A at distance 5 cm from the centre of the circle is 4 cm. Find the radius of the circle.
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The length of a tangent from a point A at distance 5 cm from the centre of the circle is 4 cm. Find the radius of the circle. Q.6
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Draw the diagram as shown below.
Here, AB is the tangent that is drawn on the circle from a point A.
So, the radius OB will be perpendicular to AB i.e. OB ⊥ AB
We know, OA = 5cm and AB = 4 cm
Now, In △ABO,
OA2 =AB2+BO2 (Using Pythagoras theorem)
52 = 42+BO2
BO2 = 25-16
BO2 = 9
BO = 3
So, the radius of the given circle i.e. BO is 3 cm.