Answer:
178.3 mm²
Step-by-step explanation:
Surface area = Base area + 3 x side triangles area
Sₐ = 43.3 + 3 x (1/2 x (10 x 9)) = 43.3 + (3 x 45) = 178.3
He is correct.
The further away ( to the left) from 0 a negative number is the smaller it is.
One vertex the rectangle lies on the straight line x + y = 6, which means that the sum of lengths of two adjacent sides is 6. Then the perimeter is 12 cm.
