TenMarks teaches you how to find the area of rectangles.
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Learn About Area of Rectangles So in the problem, we need to find the area of the rectangle. Before we begin, let’s review. So a rectangle is a polygon that has four sides. Now, in the rectangle, the opposite sides are equal in length as well as all the angles are equal in measure. Now, the area of a figure—so if you’re looking at the area of a figure—the area of a figure is the measure of the size of the region enclosed by the figure. So it’s the measurement of the size of the region enclosed by a figure. When you’re measuring area, you measure in square units. So for example, square inch would be inch2 or square feet would be feet2. Alright. Let’s take a look at this rectangle and find the area. So the area of the figure is when you measure the size of the region enclosed by a figure. So one way of calculating the area of a figure is to place it on a grid of squares such as this. These are unit squares. Now, the squares are arranged into rows and each row contains the same number of squares. The area is the number of square units that lie within the figure. So the area is a the number of square units that lie within this figure. So to find the total number of squares that cover the rectangle, we’re going to multiply the number of rows of squares by the number of squares in each row. So to find the total number of squares, we’re going to multiply the number of rows by the number of squares in each row. So this rectangle encloses four rows, one, two, three and four. So we have four rows, and then each row has six squares. Now, let’s plug these in to find our total number of squares. So our total number of squares is equal the number of rows which we know is 4 x the number of squares per row which we know as 6. So 4 x 6 is 24. So 24 unit2 are enclosed within the rectangle. So the area of the rectangle would then be 24 unit2, so that’s how we would label it. Now, let’s note and pay attention that the width of the rectangle, how wide the rectangle is, is equal to the number or rows. So your number of rows equals the width of your rectangle. So this side would be your width. Now, the length of the rectangle is the number of squares in each row. So the number of each squares in each row equals your length. So this would be your length up here. So if we wanted to know the area of a triangle which the area of the rectangle is the total number of squares, it’s this total area of the rectangle. The area of the rectangle would be equal to the number of rows which we know is the width x the number of squares per row which we know is your length. So to find the area of the rectangle, you multiply the width x length, and the formula would be A = W x L. Now, remember that we can use this formula to calculate the area of any triangle. Let’s move on to B. Here, we have a school building that measures 30 ft x 30 ft, how much land does it cover. So, we know that the school building measures 30 ft x 30 ft, and this is a square. So since the length and width are the same, this tells me that this is a square. Now, a square is a special form of a rectangle because it has four equal sides. So that means that if it has four equal sides, the lengths equals the width. Now, to find out the area—so the area of land, how much land does it cover. So the area of land covered will equal the area of the square or the building. So to find the area of a square—the area of the square with the sides S. We’re going to use the formula S x S, and S = LW, so our formula is S2. So find the area, we’re going to take our S2 or the length and the width, so it’s going to be 30 x 30, since it’s the same, it’s just 302. 302 is 30 x 30. So if we multiply or square 30, we get 900 ft2. And please note that the unit ft2 means that we did ft x ft. So that’s what ft2 means. So the area of land covered by the school building is 900 ft2. Alright, remember that the area of the square with side S is S2. Okay, things to remember and keep in mind is that to find the are of a figur