$\bf \textit{area of a circle}\\\\
A=\pi r^2\quad 
\begin{cases}
r=radius\\
-----\\
A=452.16
\end{cases}\implies 452.16=\pi r^2\implies \cfrac{452.16}{\pi }=r^2
\\\\\\
\boxed{\sqrt{\cfrac{452.16}{\pi }}=r}\\\\
-------------------------------\\\\
\textit{circumference of a circle}\\\\
C=2\pi r\qquad \qquad \implies C=2\pi \left( \boxed{\sqrt{\cfrac{452.16}{\pi }}} \right)$

so, is just that product, recall to use "<span>3.1416 as the value of π".</span>

7 0

3 years ago

B is the midpoint of AC and E' is the midpoint of BD. If A(-9,-4), C(-1, 6), and E(-4,-3), find the coordinates of D.

Ipatiy [6.2K]

The coordinates for D are (-4, -7)

First we must locate point B as it is vital to finding the midpoint of BD. To do this, we take the average of the endpoints AC since B is its midpoint.

x values = -9 + 1 = -8
Then divide by 2 for the average -8/2 = -4

y values = -4 + 6 = 2
Then divide by 2 for the average 2/2 = 1

Therefore B must be (-4, 1)

Now we know the values of E must be the average of B and D. So we can write equations for each coordinate since we know they are averages.

x - values = (Bx + Dx)/2 = Ex
(-4 + Dx)/2 = -4 ---> multiply both sides by 2
-4 + Dx = -8 ---> add -4 to both sides
Dx = -4

y - values = (By + Dy)/2 = Ey
(1 + Dy)/2 = -3 ---> multiply both sides by 2
1 + Dy = -6 ---> subtract 1 from both side
Dy = -7

So the coordinates for D must be (-4, -7)

5 0

3 years ago

Read 2 more answers

Solve the inequality <br> 3(x-2)>-3

wolverine [178]

Answer:

x>1

Step-by-step explanation:

m at h w ay

6 0

3 years ago