Question

In a circle with centre A chord BC is of length 80cm also if AD perpendicular BC and AD= 9 cm then find the length of the diameter of the same circle​

Answer 1

As we know that chord BC has its two endpoints B and C on the circle .

So if we join centre A with C which is lying in the boundry of the circle then

AC is the radius .

Now in ▲ADC , ∠D = 90° , AD = 9cm , CD= 40cm { because we know that if chord id perpendicular to the radius it gets bisected }

So, using Pythagoras Therom,

AC² = AD² + CD²

AC² = 9² + 40²

AC² = 81 + 1600

AC² = 1681

AC = 41

So radius = 41cm

So , Diameter of the circle is 82.

Answer 2

Answer:

82cm

Step-by-step explanation:

see answer in the picture