Sin cos and tan are basically just functions that relate an angle with a ratio of two sides in a right triangle. Sin is equal to the side opposite the angle that you are conducting the functions on over the hypotenuse which is the longest side in the triangle. Cos is adjacent over hypotenuse.
11. 2x+3x+1=21
5x+1 =21
5x=20
x=4
TU= 2(4) which is 8
UB= 3(4)+1 which is 13
12. 4x-1 +2x-1=5x
6x-2=5x
-2=-1x
2=x
X=2
TU= 7
UB= 3
TB=10
Problem 13:
2x-8=x+17
2x=x+25
x=25
AB =42
BC=42
AC=84
Problem 14:
3x-31
-x+6
=
2x-37 for BC part now we solve for x
x+6=2x-37
6=x-37
43=x
So :
X=43
AB=49
AC=98
BC=49
I think the ratio would be 3.5 : 1

Square 12.1, and subtract 121 from both sides.

Complete the subtraction on the right side.

This is the solution.
2(x+2) = 60
x+2 = 30
x = 28
The correct answer is C