so, is a semi-circle, half a circle, recall a circle has a total of 360°, so half of that will be 180°.
the diameter of that circle is 10, so its radius is half that, or 5.
![\bf \textit{arc's length}\\\\ s=\cfrac{\theta \pi r}{180}~~ \begin{cases} r=radius\\ \theta =angle~in\\ \qquad degrees\\[-0.5em] \hrulefill\\ \theta =180\\ r=5 \end{cases}\implies s=\cfrac{(180)(\pi )(5)}{180}\implies s=5\pi \stackrel{\pi =3.14}{\implies s=15.7}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Barc%27s%20length%7D%5C%5C%5C%5C%20s%3D%5Ccfrac%7B%5Ctheta%20%5Cpi%20r%7D%7B180%7D~~%20%5Cbegin%7Bcases%7D%20r%3Dradius%5C%5C%20%5Ctheta%20%3Dangle~in%5C%5C%20%5Cqquad%20degrees%5C%5C%5B-0.5em%5D%20%5Chrulefill%5C%5C%20%5Ctheta%20%3D180%5C%5C%20r%3D5%20%5Cend%7Bcases%7D%5Cimplies%20s%3D%5Ccfrac%7B%28180%29%28%5Cpi%20%29%285%29%7D%7B180%7D%5Cimplies%20s%3D5%5Cpi%20%5Cstackrel%7B%5Cpi%20%3D3.14%7D%7B%5Cimplies%20s%3D15.7%7D)
(7.2 × 10^7) ÷ (9 × 10^4)
= (7.2 / 9) x 10^(7 - 4)
= 0.8 x 10^3
= 8 x 10^2
Answer
C. 8 × 10^2

= 7.
Ratio means multiply/divide.
To get the next number, multiply number by common ratio.
To get a previous number, divide by common ratio.
Since we want the next number...
2nd term: 7 x -2 = -14
3rd term: -14 x -2 = 28
4th term: 28 x -2 = -56
5th term: -56 x -2 = 112
Keep going until 9th term!
Exponential notation allows the representation of numbers in shorter form.
(2 x 2 x 2)(4x4x4) = 2x2x2x2x2x2x2x2x2
Angle F should be 46 degrees