Triangle CDE = KFM and both are isosceles. find the perimeter of triangle KLM if side CD = 10 cm.

triangle CDE and triangle KFM are equilateral.

All sides of a regular triangle are equal to each other, all angles are also equal and amount to 60 °.

1) By the condition of the triangle CDE = triangle KFM, and hence CD = DE = CE = KF = FM = KM;

2) We are also given a side CD = 10 cm, and based on point 1, we can say that either side of triangle CDE and triangle KFM is 10 cm.

3) Now we can find the perimeter of the triangle KFM, and the perimeter is the sum of all the sides of the triangle.

P (KFM) = 10 cm + 10 cm + 10 cm = 30 cm.

Answer: P (KFM) = 30 cm.