\pi (5)^2 = 25\pi \text{ μm}^2

February 22, 2026

$\pi (5)^2 = 25\pi \text{ μm}^2$

Related Articles

Thus, $ \frac{h}{r} = \boxed{4} $.
Question: A palynologist observes a pollen grain with a circular cross-section of diameter 10 micrometers, and inside it, a spore with a square cross-section inscribed such that its vertices touch the circumference. What is the area, in square micrometers, of the region within the circular grain but outside the square spore?
Solution: The circle has radius $ 5 $ micrometers, so its area is:
The square is inscribed in the circle, so its diagonal is the diameter, 10 μm. For a square, diagonal $ d = s\sqrt{2} $, so:
s = \frac{10}{\sqrt{2}} = 5\sqrt{2} \text{ μm}
The area outside the square but inside the circle is:

Trending Articles