Word Problem 4
Problem 4: You started from a place and went 4 km north and turned left and moved 2 km west. Then you again turned left and moved 2 kms. How many kilometers are you from the place you started ?
a. 4km b. 2km c. 6km d. 10 km
— end point and start point mathematics, ray math definition –
We draw path as below
Let S be the start point and first movement is from point S to point B – 4 kms in the north direction. At point B you turned left (west) and moved 2 kms and reached point C. Then you turned left again (South) and reached point E.
If we join point E to the line SB then it will touch it at point A – which is mid of the way S to B. So, A to B will be of 2 km length as well.
We join point E with S by a double line. We have to find the length of this double line which will be the distance of your last location E from the start point S.
Clearly here S to A to E is a right angled triangle !
We use Pythagoras Theorem to find the length E to S
SA=2 (because A is mid of 4 km line SB)
AE=2 (because EA is parallel to BC line and equal in length)
Put values in expression;
So, you will be 2.82 km from your start point