Question: If you like this sort of argument, apply it to the Sun. Curiously, the Sun subtends at Earth almost exactly the same angle as the Moon, although the Sun is more distant. As you saw in Example 9, knowing the Sun is about 1.5 × 1011 m from Earth, you can find its diameter. What is its volume? How does that volume compare to Earth's?
Example: The Moon subtends an angle of ≈0.5? from a point on the Earth. The Sun also subtends an angle of ≈0.5? from Earth. If the Sun is 1.5×1011 m from Earth, what is the Sun's diameter? This angle is about 8.7 mrad. Therefore the diameter of the Sun is 8.7×10-3×1.5×1011 m = 1.31 × 106 km