Answer:
280cm^
Explanation:
1 square 10x10 = 100
1 rectangle 20x6 = 120
1 rectangle 18x4=72
subtraction of hallf of a rectangle 6x4=24 (half = 12)
100+120+72= 292
292-12=280
1 square at the top (10x10) 100
1 rectangle at the bottom(20x6) 120
1 rectangle in the middle with a missing part (18x4)= 72
4+5+3+? =18
?=18-12
?=6
The missing part is half of 6x4 24/2 =12