Question

I need help on this question it’s urgent please help

Answer 1

To answer this question, we define the angles a, b and c from the picture below:

From the picture we see the following:

1) The lines t and l_1 are perpendicular because the angle between them is equal to 90°.

2) The angles 120° and b are supplementary, so they sum up 180°. Taking to account this, we have:

`\begin{gathered} 120^(\circ)+b=180^(\circ), \\ b=180^(\circ)-120^(\circ)=60^(\circ)\text{.} \end{gathered}`

3) The angles c and 60° are supplementary, so they sum up 180°. Taking to account this, we have:

`\begin{gathered} c+60^(\circ)=180^(\circ), \\ b=180^(\circ)-60^(\circ)=120^(\circ)\text{.} \end{gathered}`

From points 2 and 3 we conclude that lines l_2 and l_3 are parallel.

Answer

a.