4mins---->12 cars
6mins---->(6*12/4)=18
4mins---->12
5mins---->(5*12/4)=15
And so on
This is a question that can be solved with Pythagorean Theorem since it is a right triangle. The longest side, 29, is the hypotenuse and the sides 21 and x are the legs. So, the Pythagorean Theorem states,

Where,
c is the Hypotenuse, a and b are the legs. Putting the respective values gives us,

So, 20 is the side length of x.
ANSWER: 20
The answer is 13
If R=4 the the equation would be 4+9 which equals 13.
We have to find the area of the floor in order to know how many square meters of flooring they need.
The area of the floor is:
42 m* (39 m)= 1,638 m^(2)
They need 1,638 m^(2) of flooring.
Hope this helps~