A quarter of the circle is shown in the figure and another circle is inscribed in it. The length of AB is 2√2 cm.
What is the circumference of the smaller circle?
a) 2√2π cm
b) 2√2π/(1+√2) cm
c) 4√2π cm
d) 4√2π/(1+√2) cm
Answers
Answer:
a is answer
Step-by-step explanation:
it is help for you
Let radius of inscribed circle be x
[ AB and BC are tangents to the inscribed circle ]
Explanation of diagram :-
▶️ OM = ON ( radius of same circle )
▶️ BP = AB = BC ( radius of quater of circle )
▶️ Now, in quadrilateral MONB , all the angles measure 90° and sides OM and ON are equal. Therefore , the given quadrilateral is a square.
Now , first we will find out diagonal OB of square MONB.
➡️OB² = BN² + ON²
➡️OB² = x² + x²
➡️OB² = 2x²
➡️OB = √2 x
Now, OB + OP = BP
➡️ OB + OP = 2√2 ( AB = BP = 2√2)
➡️ √2 x + x = 2√2
➡️ (√2 +1) x = 2√2
➡️ x =( 2√2 )/ (√2 +1)
radius of inscribed circle = ( 2√2 )/ (√2 +1) cm
Circumference of circle = 2π × radius
➡️Circumference of circle =2π × ( 2√2 )/ (√2 +1)
➡️Circumference of circle = (4π√2 )/ (√2 +1) cm
Answer :-
option (d) 4√2π/(1+√2) cm is correct