Answer:
The roads are 4 km , 4 km, 4 km , 4 km and 6 km.
Explanation:
From the first diagram below, for the 4 cities to be connected all the roads will be 32 km but the budget only allows for 22 km roads. The second diagram demonstrate how you could build a 22 km road that connects the 4 cities.
The square ABCD all the sides are equal. Base on the diagram 2 triangles are formed.
The length of the hypotenuse can be found using Pythagoras formula.
c² = a² + 4²
c² = 16a²
square both sides
c = √16a²
c = 4a
The hypotenuse of the right angle triangles formed are 4a.
The length of the line joining the 2 triangles can be solved as 8 - a - a = 8 - 2a.
Now recall the roads all together is 22 km.
Therefore,
add the hypotenuse of the 4 right angle triangle and 8 - 2a to connect the 4 cities.
4a + 4a + 4a + 4a + 8 -2a = 22
16a -2a + 8 = 22
14a + 8 = 22
14a = 22 - 8
14a = 14
a =14/14
a = 1
replace the value of a in all the sides
the road will be
4(1) + 4(1) + 4(1) + 4(1) + 8 - 2(1) = 22 km
The roads are 4 km , 4 km, 4 km , 4 km and 6 km.