Question 568377: The sides of a triangle have lengths of (3x-5),(x-7) and (7x+12). What is the perimeter of the triangle in terms of X? Answer by bucky(2189) (Show Source):
You can put this solution on YOUR website! You are given that the three sides of the triangle have lengths of 3x-5 and x-7 and 7x+12.
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The perimeter of a polygon in plane geometry is found by adding the lengths of all the sides. Therefore, the perimeter of this triangle is found by adding the three lengths of the sides. This can be done as follows:
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Perimeter = 3x-5 + x-7 + 7x+12
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Algebraically add together all the terms containing x. This involves adding 3x+x+7x and the sum of 3+1+7 = 11. So combining the terms containing x results in an answer of 11x.
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Then algebraically add together all the constants. This involves adding -5 -7 and +12. Notice that when you add these the result is zero since -5 plus -7 equals -12 and when added to +12 cancels out to zero.
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This means that the perimeter of this triangle is 11x + 0 or just 11x.
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I hope that this helps you to better understand how to find the perimeter of plane figures when each of the sides is given by an algebraic expression.
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