(7)
if r perpendicular to s then angles 1,2,3,4=90 deg.
if t perpendicular to s then angles 5,6,7,8=90 deg.
If two different lines intersect a third line at the same angle then they must be parallel.
r and t intersect s at the angle 2=90 deg and 6 = 90 deg, therefore r and t are parallel.
(6) use sum of angles in a triange =180 deg property.
first, the complement to 105 is an angle of 75 deg. then x=180-(24+75)=81 deg
x=81 deg
(5)
[tex]\angle STU=180-\angle STR=180- \angle SRT \\\\\4x = 180-20=160\\\\x=40[/tex]
(4) sum of angles = 180 deg
62 +45 + k = 180
k = 180 -107 = 73
k = 73
