Answer:
4 1/3
Step-by-step explanation:
12/3=4
1/3+4=4 1/3
Well, notice the composite is really just 4 triangles atop sitting on top of 4 rectangles, and all of them area stacked up at the edges.
so, for the rectangle's sides,
front and back are two 6x3 rectangles
left and right are two 6x3 rectangles
the bottom part is a 6x6 rectangle
now, we don't include the 6x6 rectangle that's touching the triangles, because that's inside area, and is not SURFACE area, so we nevermind that one.
now, the triangles are just four triangles with a base of 6, and a height of 4, in red noted there.
so, just get the area of all those rectangles and the triangles, sum them up and that's the
surface area of the composite,
Answer:
There's supposed to be nothing in the 7 and 8 columns
Step-by-step explanation:
You were good, but there aren't any in the 7 or 8 columns, making 9 an outlier.
hope this helps:)
There are two ways you can do this. You can use the longer way:
15+16+17+18+19+20+21+22+23+24 = 195 (starting from the top row, which has 15 logs, up until the bottom row, which has 24 logs, on condition that each second row has one log more than the previous one)
You can also use the formula (where n is the number of rows)
x= (n(first term+last term))/2
x= (10(15+24))/2
x= (10*39)/2
x=390/2
x=195
Either way, there are 195 logs in the stack.