Answer:
243 cm^2 + 108 cm^2 = 351 cm^2
Step-by-step explanation:
So, we have a rectangle and two triangles, we know all the sides or angles.
Rectangle: with 9 cm lenght 15cm + 12 cm = 27 cm
Formula: A=wl -> A=9*27 = 243 cm^2
Trianlge: A=ab/2
Angle 90°
Side A 12 cm
Side B 18 cm - 9 cm = 9 cm
A=ab/2=12·9/2=54 cm times 2 (for the opposite side) = 108 cm^2 = 351 cm^2
