The correct answer is y=28 cm
Explain
Area of 4 congruent parallelograms= 308cm^2
Area of 1 parallelogram = 308/ 4
Area of 1 parallelogram = 77 cm ^2
h+h= 14
As h+h=2h
2h=14
Divide both side by by 2
H= 7
Solve for b
As b+b = 2b
2b+6=y
Subtract both side by 6
2b+6-6=y-6
Combining numbers
2b=y-6
Divide both side by 2
2b/2 = y-6/2
Cancel 2
B= y-6/2
We have of 1 parallelogram = 77 cm^2
H= 7
B= y-6/2
Parallelogram area = bh
So now parallelogram area = y-6/2 x7
And area of 1 parallelogram = 77 cm^2
Y-6/ 2 x 7 = 77
Y-6/2 x 7= 7(11)
Cancel 7
Y-6/2 = 11
Multiple both by 2
2(y-6/ 2) = 11x2
Cancel 2 and multiple numbers
Y-6=22
Add 6 both sides
Y-6+6=22+6
Y=28