Both angles are complementary and add up to 90 degrees. If you do that in an equation it should be like this:
2x + 14 + x + 7 = 90
Simplify:
3x + 21 = 90
3x = 69
X = 23
Now just plug that into angle CBD and you get:
2(23) + 14 = y
46 + 14 = y
60 = y
Angle CBD is 60 degrees
There are 4 triangles with base of 5 and height of 8.4
Area of triangle = 1/2 x base x height
Area of triangle = 1/2 x 5 x 8.4 = 21 m^2
Multiply by 4 = 21 x 4 = 84 m^2
Area of the base = length x width = 5 x 5 = 25 m^2
Total area = 84 + 25 = 109 m^2
