Answer:
Its really simple look it up at some site
Length of the side = 9 cm
Diagonal =
cm
Solution:
Area of the square = 81 square centimeters
In square all sides are equal.
Area of the square = side × side
Side × side = 81
Side² = 9² (∵81 = 9²)
Taking square root on both sides, we get
Side = 9 cm
Length of the side = 9 cm
To find the length of the diagonal:
In square all the angles are right angle.
Diagonal splits the square into two right angle triangle.
Using Pythagoras theorem,
<em>In right triangle, square of the hypotenuse is equal to the sum of the square of the other two sides.</em>
Here, diagonal is the hypotenuse.



Taking square root on both side,
Diagonal =
cm
<span>We know I kilometer = 0.62 miles and 1 liter = 0.26 gallon. Therefore, 12.4 km/liter = 12.4 * 0.62 miles / 0.26 gallon = 29.56 miles/gallon or we can right as aprproximately 30 miles/gallon. Thus, 12.4 km/l corresponds to 30 miles/gallon.</span>