1) A
2) B
3) D
4) C
You are told #1, so it is given
A line has 180°, so if that line is interested, both parts add up to 180°- because lines c and d are parallel and both intersected by line t, the measurement of alternate angles will be the same
Angles 5 and 8 are across from each other on two intersecting lines, so they will have the same measurement
Substitution is the only answer left
