# Significant figures

I have a question about the significant figures topic:

Problem: Find the volume of a cylinder having a diameter measured as 2.3 ft and length measured as 8.25 ft.

Solution: V = π(D^2 /4)h = π((2.3)^2)(8.25)/4 = 34.276739 cu ft = 34 cu ft

Question:
In my workbook is explained that the final answer is rounded to two significant figures because the quantity 2.3 has two significant figures.
Why will I have to round to two significant figures if the quantity 8.25 have three significant figures?

• Writing in all capitals doesn't make it more significant. Oct 23 '17 at 14:40

$\frac{Var(volume)}{Vol^2} = \frac{\pi}{4} *( 2*\frac{Var(diameter)}{Diameter^2} + \frac{Var(height) }{height^2} )$