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Answer:</h2>

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Step-by-step explanation:</h2>
This is a square pyramid because it's a solid having a square base. The point up the pyramid is called the apex and is directly above the middle of the square base. The surface area of a solid is the total area of its outer surface. If we unfold this pyramid, we'll get one square and four identical triangles. So the surface are can be calculated as follows:

FOR THE SQUARE:
FOR THE TRIANGLE:

Finally:

Answer:
NOT proportional
Step-by-step explanation:
y/x = 5/2 = 2.5
y/x = 6/3 = 2
also 7/4 = 1. 75 and 8/5 = 1.6 so:-
They are NOT proportional
The answer is 51 because 180-139=51
Answer:
281760000 thats expanded form
2.8176 x 10 8 this is notation
if you have any troubles ask me im new to brainly so have a good day