There are 20 people in a room. if every person shakes hands with every other person, how many handshakes will there be altogether? number of handshakes=?

400

Step-by-step explanation: if everyone hand shakes every other person the answer will be 400, because 20 times 20 is 400

hope I helped.

idk

step-by-step explanation:

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have