Area = \frac{a X p}{2}
Area = apothem times perimeter over 2
Answer:
let required no be x

by doing crisscrossed multiplication

42=7x
dividing both side by 7

6=x
therefore x=6
therefore value of remaining no.is 6
The answer to 14 is 13 as in the number not the question
and 13 I'm not so sure