Base on the diagram you give and the choices where there is two triangle that both have vertexes, lines and segment. By calculating and analyzing the diagram , I conclude that the answer would be D. BD is congruent to RT. I hope i answered your question

This happens whenever

or

. More generally,

whenever you start with one of these angles and add any multiple of

, so the general solution would be

, where

is any integer. (Notice that when

, you end up with

.)
y = 80x - 60
Answer is B. y = 80x - 60
Double check:
When x = 1, y = 80(1) - 20 = 80 -60 = 20
When x = 2, y = 80(2) - 20 = 160 -60 = 100
When x = 3, y = 80(3) - 20 = 240 -60 = 180
When x = 4, y = 80(4) - 20 = 320 -60 = 260
When x = 5, y = 80(5) - 20 = 400 -60 = 340
The answer would be 1.3 x 10 -5