Find x and y and all marked sides or angles of the given par
     Find x and y and all marked sides or angles of the given parallelograms.   
  
  Solution
a. x and 40 are alternate interrior angles
 x= 40
In triangle ACD, cad + 110 + x = 180
cad +110+40 = 180
 cad = 30
bca = cad = 30, alterate interior angles
In triangle bca, bca +40+30 = 180
 bca = 110
y = 110
b) Now lengths of the 2 halves of the diagonals are equal.
So, 2x+1 = x+4
 x = 3
y+1 = 2y-3
 y = 4

