Question

in a Circle two parallel chord of length 8cm and 4cm are 2cm apart what is the radius of the Circle​

Answer 1

Answer:

AB=8cm

CD=6cm

PQ=1cm

Let radius of the circle be r

Therefore,

OA=OC=r

We know that the perpendicular dripped from the centre of the circle on the chord bisects the chord.

Therefore,

CQ=QD=3cm

AP=PB=4cm

Let OP=x

=>OQ=x+1

Now,OA2 =OP2+AP2

=>r2 =x 3 +42

=>r2=x2+16 (i) OC2+OQ2+CQ2

=>r2=(x+1) 2+32

=>r2=x2+2x+1+9

=>x2+16=x2+2x+1+9 (from (i)

=>2x=6

=>x=3

Therefore,r2=32+16

=>r2=9+16

=>r2=25

=>r=5cm