Practicing Success
P is a point outside a circle with centre O, and it is 14 cm away from the centre. A secant PAB drawn from P intersects the circle at the points A and B such that PA = 10 cm and PB = 16 cm. The diameter of the Circle is: |
10 cm 11 cm 12 cm 13 cm |
12 cm |
Given OP = 14 cm, PA = 10 cm, PB = 16 cm Let radius of circle be r cm. = OQ = OE = r cm = PR = (14 - r) and PQ = (14 + r) As we know, PE x PQ = PA x PB = (14 - r)(14 + r)= 10 x 16 = \( { 14}^{2 } \) - \( { r}^{2 } \) = 160 = 196 - \( { r}^{2 } \) = 160 = \( { r}^{2 } \) = 196 - 160 = 36 = r = \(\sqrt {36 }\) = 6 cm Therefore, Diameter 2 x 6 = 12 cm. |