Answer:

Step-by-step explanation:
See attachment for complete question.
From the attachment, we have:

-- Radius
Required
Determine the area of the sector
Area (A) of a sector is calculated as:

Substitute values for r and 




Take
as 



<em>-- approximated</em>
Answer: The length of BC ≈ 12.4 cm
Step-by-step explanation:
The first thing we need to do is to find the length of BD which we can solve for with the tangent of 20° which is the opposite side over the adjacent side.
We get tan20° = BD/8.
Solve for BD and you get BD = 8tan20°.
Now we will need to solve for the length of CD which we can get from the tangent of 40°.
We get tan40° = 8/CD
Solve for CD and you get CD = 8/tan40°.
Now that we have the lengths of BD and DC, we can simply add them together to get the length of BC.
(8tan20°) + (8/tan40°) ≈ 12.4 cm
Number of different selection = 50C6
Number of different selection = 50 x 49 x 48 x 47 x 46 x 45
Number of different selection = 15 890 700
Answer: 15 890 700