Answer:
Note :
The perimeter is : AB + BC + CA
AB =√((XB - XA)² + (YB - YA)²) = √((16-2)²+(2-8)²) = √(12²+6²) = √(144+36)=√180
AB = √(36×5) = 6√5 units
same method for : BC ; CA ..........
Tangent theta = opp/adj = 48/36 = 4/3
Since y is .95 and x is 1 it is a unit rate which is the constant of proportionality.
Correct me if I am wrong.
Cosine is the ratio of the adjacent side to the hypotenuse.
In short, we have this equation
cos(angle) = adjacent/hypotenuse
In the case of cos(A) = 18/19.5 we can see that
adjacent = 18
hypotenuse = 19.5
The side of 18 cm is next to angle 2, so the 18 cm side is adjacent to angle 2 (in contrast, the 7.5 cm side is the opposite leg in relation to angle 2)
So that's why the answer is angle 2
In other words, replace the '2' angle marker with 'A' to be able to write cos(A) = 18/19.5
2/5 at the top nd bottom, but 0/5 on the sides. So 2/5 + 0/5= 1/5