In parallelogram ABCD, the height BK divides side AD into segments AK and KD.

In parallelogram ABCD, the height BK divides side AD into segments AK and KD. Find the perimeter of the parallelogram if BK = 8cm, DB = 10cm, AK = 15cm.

1. The side AB of the parallelogram is the hypotenuse in the right-angled triangle ABK.

Using the formula of the Pythagorean theorem, we calculate its length:

AB = √AK ^ 2 + BK ^ 2 = √15 ^ 2 + 8 ^ 2 = √289 = 17 cm.

2. Calculate the length of the segment KD:

KD = √BD ^ 2 – BK ^ 2 = √10 ^ 2 – 8 ^ 2 = √100 – 64 = √36 = 6 cm.

3. AD = AK + DK = 15 + 6 = 21 cm.

4. Opposite sides of parallelogram ABCD are equal. Therefore, AB = DC.

BC = AD.

5. The perimeter of the parallelogram ABCD = 2AB + 2BC = 17 x 2 + 21 x 2 = 76 cm.



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