A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 5 years ago
Which of these is the closest approximation of the area of a circle with a radius of 3.125 cm ?
a.)about 15 cm2
b.)about 30 cm2
c.)about 20 cm2
d.)about 25 cm2
anonymous
 5 years ago
Which of these is the closest approximation of the area of a circle with a radius of 3.125 cm ? a.)about 15 cm2 b.)about 30 cm2 c.)about 20 cm2 d.)about 25 cm2

This Question is Closed

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Area = pi times radius squared. 3.125 is roughly 3, and 3 squared is 9. pi is roughly 3, and 9 times 3 is 27. Since you estimated both numbers low, your actual answer will be greater than 27, so B.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0its b. the formula is PI * Radius squared. if you do some really rough rounding, PI = 3. now 3.125 is about 3. so using the formula, you do: 3*(3 squared) which is ABOUT 27. now you know that PI is a little bit larger than the number you just used for PI (the estimated of PI), so find a numbr a litle but larger than 27. That is 30.
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.