Practicing Success
P is a point outside a circle and is 26 cm away from its centre. A secant PAB drawn from intersects the circle at points A and B such that PB = 32 cm and PA= 18 cm. The radius of the circle (in cm)is: |
12 8 10 13 |
10 |
Let PQ = (26 + r) and PT = (26 - r) As we know, = PT x PQ = PA x PB = (26 + r) x (26 - r) = 18 x 32 = \( {26 }^{2 } \) - \( {r }^{2 } \) = 576 = \( {r }^{2 } \) = 676 - 576 = \( {r }^{2 } \) = 100 = r = \(\sqrt {100 }\) = 10 cm. |