To solve this problem you must apply the proccedure shown below:
1. By definition, the opposite sides of a parallelogram are parallel and have equal length.
2. The figure attached shows that the opposite sides with equal length are:

3. Keeping this on mind, you have that the side <em>c</em> and <em>a</em> are equal and measure six centimeters.
4. To find the length of the other sides, you must apply the following formula for calculate the perimeter of a parallelogram:

4. If you solve for <em>b</em>, you will obtain the measure of <em>b </em>and<em> d:</em>

Therefore the answer is:
The lengths of the sides are: 6 cm, 6 cm, 9 cm and 9 cm.
Answer:36
Step-by-step explanation:

for every 7 students there are 4 girls, so for every 84 there must be 48
7*12=84
4*12=48
so, in all 84 students there are 48 girls
so amount of boys=84-48=36
there are 36 boys
Answer: The answer for f= 3.1