Formula :
Perimeter of Trapezium = sum of all sides
AB + BD + EC + BC [Refer to the attachment]
AB = 14 cm
EC = 6 cm
BD = 8 cm
Let's find the length of side BC
In right angle triangle , BDC
EC = 14 cm
AB = 6 cm
DC = EC - AB
= 14 - 6
= 8 cm
According to Pythagoras theorem,
BC² = DC² + BD²
BC² = 8² + 8²
BC² = 64 + 64
BC = √128
BC = 11.31 cm
Perimeter = sum of all sides
= 14 + 6 + 8 +11.31
= 20 + 8 + 11.31
= 28 + 11.31
= 39.21 cm (Answer)