Answer:
418 4/10
Step-by-step explanation:
To answer this we subtract 450 7/10 from 869 1/10.
We must borrow a '1' from 869 1/10: 868 11/10
Now subtract 450 7/10 from 868 11/10:
418 4/10 (CHANGE IN ELEVATION)
This reduces to 418 2/5.
The formula for the area of the triangles is base x hight divided by 2 (bh/2)
The formula for the square is length times width (l x w)
therefore...
bh/2 = (12)(6) / 2 = 36 (this is the area of one triangle)
then you need to times 36 by 4 because you have 4 triangles.
36 x 4 = 144
l x w = 12 x 12 = 144 (this is the area of the square)
last you need to add the area of the triangles (144) and the area of the square (144) because that will give you the total surface area of the shape.
144+144= 288
so your answer is 288cm squared (288cm2)
