Answer:
The measure of the sides is 20 cm.
Step-by-step explanation:
Opposite side of a parallelogram:
Opposite sides of a parallelogram are congruent, that is, they have the same measure.
Measures (2x+10) cm and (x+15) cm:
This means that:
2x + 10 = 2*5 + 10 = 10 + 10 = 20
The measure of the sides is 20 cm.