HELP ME PLEASE!!!this is due in 10 minutes The lengths of the sides of a triangle are x,2x and 2x centimetres. If the perimeter is 20 centimeters, what is the value of x?

a)4
b)5
c)8
d)10​

Acoin is tossed twice. let e e be the event "the first toss shows heads" and f f the event "the second toss shows heads". (a) are the events e e and f f independent? input yes or no here: yes (b) find the probability of showing heads on both toss. input your answer here: preview

I'm terrible at math any here is appreciated.

Determine whether the quadrilateral below is a parallelogram. justify/explain your answer (this means back it up! give specific information that supports your decision. writing just "yes" or "no" will result in no credit.)