Answer:
2 - 
Step-by-step explanation:
Using the addition formula for tangent
tan(A - B) = 
and the exact values
tan45° = 1 , tan60° = , then
tan15° = tan(60 - 45)°
tan(60 - 45)°
= 
= 
Rationalise the denominator by multiplying numerator/ denominator by the conjugate of the denominator.
The conjugate of 1 + is 1 -
= 
← expand numerator/denominator using FOIL
= 
= 
= 
+ 
= 2 -
Answer: 85.104
Step-by-step explanation: Adding decimals is something you will use a lot. Take the time to learn it now. So when you are adding decimals there are some important things to keep in mind. 1. Line the decimals up. Let me explain. Lets do a example. Lets say its 14.5+ 15.74. The first thing you would need to do is line them up like this-->
14.5
15.74
+____
After you do that, Do you see a black space next to the 14.5? When adding decimals this is a big nono. So what you can do is add a 0. Adding a zero is only applicable when you have one number that has 1 more number(its my best way to explain it).( so like you would add a zero if your equation was like 23.5 +18.99. but you wouldn't do it if it was 17.5+19.4). Example equation should look like this:
14.5
0<---- add the zero!
15.74
+____
Step 2. Put the decimal down to where it lines up. Like this:
14.5
0
15.74
+____
.<------ make sure it lines up!
Step 3. Add regularly. Just ignore the decimal in the equation and just add. The answer would be 30.24. If you don't know how to add, I don't think your old enough for a brainly account:)
Step 4. Remove the zero. Zero as a number means nothing. So its ok in math to add a zero at the end of a decimal. So 4.0 is the same as 4 or 4.0000000000000. So when you have another problem, and your answer is something like 95.320, you can just remove the zero. So it would be 95.32:)
Hope I Helped! (this took me a long time to type out)
:)
The answer would most commonly be C only because a square is 360 degrees and the surface area would be a 6th of that which is 60 then i multiplied it by 4 because of the four corners signaling the height and or length of the 2D figure square which gives me C.
