Find the length of the side AB, if the perimeter of the figure is 45 cm, and the sides are BC = 13cm,

Find the length of the side AB, if the perimeter of the figure is 45 cm, and the sides are BC = 13cm, CD = 10cm, DE = 7cm, EA = 5cm.

By the condition of the problem, we have a pentagon, for which the perimeter and length of 4 sides are known. To find the length of the fifth side, subtract the sum of the known four sides from the perimeter.

P = AB + BC + CD + DE + EA

AB = P – BC – CD – DE -EA

AB = 45 – 13 – 10 – 7 – 5

AB = 10

Answer: the length of the AB side is 10 cm.



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