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

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

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

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

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: