Definition of "radii" [ra•di•i]

• A plural of radius. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In other minerals the radii are a little different."
• "142 Math Wonders to Inspire Teachers and Students The familiar circumference formulas give us C C = 2 r or r = 2 and C +1 C +1 = 2 R or R = 2 We need to fi nd the difference of the radii, which is C +1 C 1 R − r = − = ≈ 0 159 yards ≈ 5 7 inches 2 2 2 Wow!"
• "As to the shape decision it is just not true we saved anything since the sidewall angle, the shoulder and heatshield radii, at the very least are NOT those of Apollo's."