Answer:
5 km
Step-by-step explanation:
You want the distance from C to A if C is 4 km east and 3 km north of A.
Triangle
Points A, B, C mark the vertices of a right triangle with legs of 4 km and 3 km. The length of the hypotenuse (C to A) is found using the Pythagorean theorem.
(AC)² = (AB)² +(BC)² = 4² +3² = 16 +9 = 25
AC = √25 = 5
The distance from C to A is 5 km.
__
Additional comment
Hopefully, you recognize this as a 3-4-5 right triangle, so you know immediately the hypotenuse is 5 km.
