First, find the scale factor between the blue pentagon and the green pentagon:
35/28 = 5/4
The ratio of the areas is 5/4
Area of the blue pentagon / area of the green pentagon = (5/4)^2
Since the area of the blue pentagon is 1050 cm2
1050 / green area = (5/4)^2
Solve for the green area:
1050/ (5/4)^2 = Green area
672 = green area
Area of the green pentagon = 672 cm2