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Find the perimeter of the rectangle.
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First of all, what does perimeter mean?
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The perimeter is the distance all the way around an object.
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We find the perimeter by adding up all the sides.
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To find the perimeter of a rectangle, we could add its four sides: side one plus side two plus side three plus side four.
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Or when we’re working with rectangles, we can multiply two times the length plus the width.
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Let’s talk about why.
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If the length is 15 centimeters and the width is 10 centimeters, the side across from the 15-centimeter length is also a length of 15 centimeters.
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The side across from the width of 10 centimeters is another width of 10 centimeters.
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Let’s then put our two different formulas side by side and solve them.
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The first version for solving the perimeter is to add up all four sides.
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We can start at the top.
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15 plus 10 plus 15 plus 10 equals the perimeter.
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Now let’s fill in our second equation.
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The perimeter equals two times the length 15 plus the width of 10.
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For the first formula, we can add up 15 and 10 plus 15 plus 10.
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Five plus zero plus five plus zero equals 10.
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We write down our zero and carry our one.
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One plus one plus one plus one plus one equals five.
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Our first formula tells us that the perimeter is 50 centimeters.
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Let’s try the second option.
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15 plus 10 is in parentheses.
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So we do that first.
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15 plus 10 is 25.
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Two times 25 equals 50.
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Both formulas give us an outcome of 50 centimeters.
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The perimeter, the distance all the way around this rectangle, is 50 centimeters.