There are: 0.5*8*5 = 20 square feet
The shape of the triangle - and its size - will determine its area. There is no information about the triangle provided and so there cannot be a sensible answer.
11236 square feet
400 square feet.
Depends on the size of the squares.
We have no problem fitting an equilateral triangle into a square. It depends on the size of the triangle and the size of the square whether one can be fit inside the other.
272 square feet. Multiply length by width - the result is the area in square feet.
There are 32 square feet in a banner of this size.
1,456 square feet. Multiply length by width - the result is the area in square feet.
10,000
There is no standard size for a kitchen.
Technically it depends on what size shoe you wear.
40,000 square feet