8.

9.
The sum of two sides must be greater than the third side.
It can't be 5 because

.
It can't be 7 because

.
It can't be 17 because

.
So it's 12.
10.
a. Turk, McAllister
b. Market, Mission, Howard
c. not sure about this one
Answer:
Step-by-step explanation:
<u>Sum of the interior angles of a regular polygon:</u>
- S(n) = 180°(n - 2), where n- number of sides
<h3>Exercise 4</h3>
<u>Pentagon has sum of angles:</u>
- S(5) = 180°(5 - 2) = 540°
<u>Sum the given angles and find x:</u>
- x° + 122° + 100° + 90° + 144° = 540°
- x° + 456° = 540°
- x° = 540° - 456°
- x° = 84°
<h3>Exercise 5</h3>
<u>Hexagon has sum of angles:</u>
- S(6) = 180°(6 - 2) = 720°
<u>Sum the given angles and find x:</u>
- x° + 110° + 160° + 105° + 105° + 115° = 720°
- x° + 595° = 720°
- x° = 720° - 595°
- x° = 125°
I think B if not type 1/3 pi 6 squared and add 6.71 or something with the 6.71