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
If you are adding a positive number to negative number. You are just bringing the negative number closer to zero, if not above zero.
Examples:
-1+1=0
-2+1=-1
-3+1=-2
-4+1=-3
8- hundreds
9-tens
0-ones
