🔍 Key Concepts

• shape of the Earth used in navigation and charting • difference between a perfect sphere and a slightly flattened body • which terms are actually used in geodesy (Earth-measurement science)

💭 Think About

• Which option best reflects that the Earth is slightly flattened at the poles and bulged at the equator? • Look at which terms are real scientific/geodetic terms versus ones that sound made‑up or informal. • For navigation and chart work, which description most closely matches how the Earth is modeled for calculations?

✅ Before You Answer

• Eliminate any option that is clearly not a standard scientific term. • Decide whether exam questions usually accept a perfect sphere as accurate, or prefer a more precise shape. • Ask yourself which term you’ve seen in nautical navigation or geodesy texts when describing the Earth’s figure.