In fig. O is the centre of circle and, OD=4 cm. If OB=5 cm then the length of tangent BC is?
Tangent is perpendicular to radius ⇒∠OCB=90∘
OD=OC=4cm
For right-angled ΔOCB,
OC2+BC2=OB2
⇒42+BC2=52
⇒BC2=25−16=9
⇒BC=3cm
In the circle shown below AB is the chord having length 8 cm and being bisected by the line OD from centre. If the radius of circle is 5 cm, then distance OD is equal to
In Fig, OACB is a quadrant of a circle with centre O and radius 3.5 cm. If OD = 2 cm, find the area of the shaded region.
In the following figure if O is the centre of the circle, AC = 3 cm and BC = 4 cm, then the length of the diameter of the circle is