The perimeter of a rectangle is 2L + 2W, or 2 times the length plus 2 times the width.  Here you're given that side BC is 4, which means that the opposite side, AD, is also 4.  So since that is two widths, you now have:

8 + 2L = 48

So 2L = 40

That means that the length is 20.

Since the area is LW, you can calculate the area as 20 * 4 = 80.

The area of a triangle is Length times Width. Here you can see that the length is 15 and the width is 10, so when you multiply 15 * 10 the answer is 150.

The area of a rectangle is Length * Width. Here you're given the width as 4, so all you need to do is find the length and you can apply the formula.

Since the width is 4 and you know that the length is twice as long, that makes the length 8. Then Length * Width would be 8 * 4 = 32.

The area of a triangle is Length * Width, and in a rectangle opposite sides are parallel and have the same length. So here you know that the widths are 2 and the lengths are 7. So multiply 7 * 2 to get your answer, which is 14.

In order to solve this problem, we need to recall the area formula for a triangle:

Now that we have the correct formula, we can substitute in our known values and solve: 

The area of a triangle is calculated using the formula .  Importantly, the height is a perpendicular line between the base and the opposite point.  In a right triangle like this one, you're in luck: the triangle as drawn already has that perpendicular line as one of the two sides.  So here we will calculate .  That gives us an answer of 24.

The area of a triangle can be calculated using the formula Area = 1/2 * Base * Height.  Here you're given two of the unknowns in that formula:

Area = 20

Height = 10

So you can plug those into the area formula to solve for Base, the only remaining unknown:

20 = 1/2 * Base * 10

That means that 20 = 5 * Base, so Base = 4.

The area of a triangle can be calculated using the formula . The height of a triangle is a perpendicular line connecting the base and its opposite point; in any acute or right triangle - a triangle with no angles greater than 90 degrees - the height is also the shortest line between the base and the opposite point.  Here that means that if you use BC = 12 as your base, then the distance of 5 between BC and point A is the height. That means that you can calculate the area:

The area of a triangle can be calculated using the formula . Note that the height of any triangle is a perpendicular line between the base and its opposite angle; in a right triangle that's very convenient, because the right angle gives you that perpendicular relationship between two sides. So you can use 24 as the base and 7 as the height here.  That means that the area is:

A perfect cube has square faces; if a face has perimeter  meters, then each side of each face measures one fourth of this, or  meters. The volume of the tank is the cube of this, or

 cubic meters.

Its capacity in liters is  liters.

 of this is 

 liters. 

This rounds to liters, the correct response.