You can prove they're congruent by SAS Postulate. You see that there are two alternate interior angels and one pair of congruent sides.
Doesn't it become like a reflection? For example instead of (3,1) it'll be (-3,-1) ?
Sin = - 4/8
Quadrant IV = only cosine is positive
a = height (4)
b = base ( 8^2-4^2=b^2
b = 6.93 @

c = hypothenuse(8)
cos =

/8
tan = - 4/

sec = 1/cos
1/cos = 1/ (

/8)
sec = 8/

csc = 1/sin
1/sin = 1/(-4/8)
csc = - 2
cot = 1/tan
1/tan = 1/(-4/

)
cot = -

/4
So for this, we will be using proportions. In this case, our proportion will be 
Firstly, cross-multiply: 36 = 3x
Next, divide both sides by 3 and your answer will be: 12 = x