Final answer:
The length of each of the two equal sides of the triangle is 18 cm.
Step-by-step explanation:
The subject of this question is mathematics, specifically geometry. According to the details provided, we are dealing with an isosceles triangle where two sides are equal. The perimeter of a triangle is found by adding up the lengths of all three sides. In this case, the perimeter of the triangle is 40 cm and the length of one side is given as 4 cm. Therefore, the combined length of the other two sides is 40 cm - 4 cm = 36 cm. Since the two sides are equal, each side is 36 cm / 2 = 18 cm. So, each of the two equal sides of the triangle measures 18 cm.
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