Question

Please helpppp

Answer 1

1. AB is a tangent line to the circle C at point B
∴ AB⊥BC  
∴ Δ ABC is a right triangle , ∠B = 90°
∴ AC² = AB² + BC²
 BC = radius = 4,000
AC = 4,000 + 22,000 = 26,000
∴ AC² = AB² + BC² = 4,000² + 26,000² = 692 * 10^6
∴ AC = √( 692 * 10^6 ) ≈ 26,306 mi


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2. ∠BAC = 9°

 Δ ABC is a right triangle , ∠B = 90°
 ∠CBA = 90°

∴ ∠BCA = 180° - (90° + 9°) = 81°
∴ the measure of arc BD which facing the satellite = 2 * 81° = 162°

while the total angel of the circle = 360°
∴ The percent of the Earth’s equator which is within range of the satellite’s signal = 162/360 = 0.45 = 45%