The first box on the left would be matched with the third box on the right, because the left one is saying that two of the sides are equal, and one angle is equal, therefore, SSA, or SAS.
The second one on the left is matched with the last one on the right, because it says that two of the angles are equal, and one side is equal, hence, AAS, or ASA.
The last one on the left is matched with the first one on the right, because it says all three sides are equal, therefore, SSS.
The third one on the left is matched with the second one on the left. I'll be honest, I'm not sure why this is, (geometry isn't my best subject either Dx) but by the process of elimination, this is it.
4 + 4 can help. Then add one.
Actually, the "slant height" is 4, but the vertical height or "altitude" of the equilateral triangle is not 4
but anyway.....

and the volume, is the area of the triangle, times the length, so, whatever you get for the area of the triangle * 10
n - 7 = 21, n= 28 should be right bc the difference of 28 and 7 is 21