Answer:
hello,
Explanation:
a)
In an isocele triangle, base's angles have the measure:
42+2a=180
2a=180-42
a=69(°)
b)
in a triangle, an external angle has for measure the sum of the angles not adjacents.
55+b=132
b=77 (°)
c)
in a quadrilater the sum of the (interior) angles is 2*180=360 degrees.
90+90+68+c=360
c=360-90-90-68
c=112 (°)