Slope(m) = -2 hope this helps
The answer is 75. You can find this using the equation 9 = 0.12x and then dividing 9 by 0.12 or 12%.
The square will have area
.. (9 cm)^2 = 81 cm^2.
The two triangles together will have area
.. (9 cm)*(12 cm) = 108 cm^2.
The sum of the areas of those three shapes is
.. 81 cm^2 +108 cm^2 = 189 cm^2