Answer: The side A measures 12 centimetres
Step-by-step explanation: Please refer to the attached picture for details.
The trapezoid is given with dimensions as shown, that is 3 cm, 5 cm, 2 cm and 2 cm. Furthermore, it is now enlarged into another trapezoid with the dimensions given as 20 cm, 8 cm, 8 cm and A cm.
Having been told that the second parallelogram is an expansion of the first one tells us that they are similar trapezoids. Hence, the ratio that makes them similar is derived as follows;
Ratio = 2:8 = 2:8 = 5:20
Ratio = 1:4 = 1:4 = 1:4
Therefore, having determined the ratio by which the trapezoid is enlarged, side A is calculated as follows;
1/4 = 3/A
A = 4 x 3
A = 12 centimetres