Geometryhard · Past Paper
In a circle with center O, PT is a tangent and PAB is a secant. If PT = 6 cm and AB = 5 cm, find PA.
A4 cm
B9 cm
C1 cm
D3 cm
✓ Correct Answer: A — 4 cm
Tangent-Secant Power Theorem: PT^2 = PA * PB. Let PA = x. 36 = x * (x + 5). x^2 + 5x - 36 = 0 => (x+9)(x-4)=0. x = 4.
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