解决涉及圆圈的问题

In This Lesson
::在本课程中

You will  apply  the formulas learned in This text will either use 3.14 to approximate or leave answers in terms of $\begin{align*}\pi. \end{align*}$  First, you'll review $\begin{align*}\pi \end{align*}$  and some of the rules for exponents. 
::您将应用此文本中学习的公式, 将使用 3. 14 来估计 或给出答案 。 首先, 您将审查 和一些 Expent 规则 。

Have Some Pi
::吃点派

You may not be familiar with leaving answers in terms of pi or even using the  $\begin{align*}\pi\end{align*}$  button on  a calculator. In the first interactive question below, sort each number below into one of the two columns:  In Terms of Pi and Numerical Approximation . Each number has a pair, so put equivalent numbers in the same row. Round answers to the nearest hundredth.
::您可能不熟悉在计算器上留下 pi 或甚至使用 按钮的答案。 在下面第一个互动问题中, 将下面的每个数字排序为两列中的一栏: 皮和数字相近。 每个数字都有一对, 因此将相等的数字放在同一行中。 圆对最接近的百次 。

Discussion Question
::讨论问题

When checking an answer to see whether or not a specific number of square units is reasonable, would it be easier or harder to check the answer in terms of pi? How would you do so?
::当检查一个答案以确定具体数量的平方单位是否合理时,用 pi 来检查答案是否比较容易或困难? 你会怎么做呢?

Use the Formulas
::使用公式

Use 3.14 for  $\begin{align*}\pi\end{align*}$  to determine the area and of the circles in the interactive. Repeat several times until you are comfortable with the two formulas. Remember the 3.14 is an estimation of $\begin{align*}\pi,\end{align*}$  but it does enable you to get a numerical answer, and not one in terms of $\begin{align*}\pi.\end{align*}$  Record your work and answers for each circle you work with.
::用于 ° 的 3. 14 用于 确定 和 互动 中 的 区域 和 圆圈 。 重复 几次 , 直到 您对 两种公式 感到满意 。 记住 3. 14 是 ° 的估计值, 但是它确实 使您能够获得一个数字答案, 而不是 ° 。 记录您的工作和 圆圈的答案 。

In this interactive, you practiced working with the formulas for exploring the dimensions of a circle. Now, you will apply them to real world situations and solve for the radius or diameter .
::在此互动中, 您练习使用公式来探索圆的维度。 现在, 您将把它们应用到现实世界中, 并解决半径或直径 。

Room for Pi?
::Pi的房间?

Ed and Sherry are putting a pool in their backyard. They want the pool to be a circle and the space they have for it is a 400 ft ² square . What is the largest diameter the pool could be? 
::Ed和Sherry在他们的后院放一个游泳池。他们希望游泳池是一个圆圈,空间是400平方英尺。该游泳池的最大直径是多少?

播放段落
• Use the interactive and adjust the red dot to make the pool its maximum size. 
  ::使用互动点并调整红点,使集合体达到最大尺寸。
播放段落
• Determine the radius and diameter of the pool.
  ::确定池的半径和直径。