Answer:
402cm
Step-by-step explanation:
middle rectangle: 10 * 12 = 120cm
top and bottom rectangles: the sides will be connected to the 8cm triangle, making their heights 8cm. 8 * 12 = 96cm
side triangles: (10 * 9) / 2= 45cm
120 + (2 * 45) + (96 * 2) = 402cm
