In the accompanying diagram, PA is tangent to the circle at A and PC is a secant. If
PA = 8 and PB = 4, then BC =
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Answer:
c. 12
Step-by-step explanation:
PA² = (BC + PB) × PB => tangent-secant theorem
PA = 8
PB = 4
BC = ?
Substitute
8² = (BC + 4) × 4
64 = 4BC + 16
64 - 16 = 4BC + 16 - 16
48 = 4BC
48/4 = 4BC/4
12 = BC
BC = 12