Answer:
10.2cm
Step-by-step explanation:
Perimeter is the sum of the lengths of all sides.
1st side: 9cm
2nd side: 7.8cm
Perimeter: 27cm
Perimeter = 1st + 2nd +3rd side of a triangle
27cm = 9cm +7.8cm + 3rd side
3rd side = 27cm - 9cm -7.8cm
= 10.2cm
Since 1 km is 100,000 cm there are 39,400 inches in a kilometer
Looks like you meant to write (p/q)³ if so it's power of a quotient
38 is 10 times more than 3.8