Question

a boy travel 5km east and then12
km south.calculate his displacement from starting point.

Answer 1

Draw a line to the left and then down. You have just drawn a triangle! Then use Pythagorean rule of A^2 + B^2 = C^2 (A squared plus B squared equals C squared.) The displacement will be the value of C.

5
▶▶▶▶▶
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[][][]▼ 12
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You have been given the legs A=5 and B=12. Solve by placing into A^2 + B^2 = C^2

Answer 2

Well my triangle didn't draw so I'll try again.

5
▶▶▶▶▶
[][][][][][]▼
[][][][][][]▼ 12
[][][][][][]▼
[][][][][][]▼
[][][][][][]▼

If you need more help. Solve the rest of this.
5^2 + 12^2 = C^2
25 + 144 = C^2
169 = C^2

Answer 3

13 is the distance, however displacement is a vector.
x = 5 (east is right)
y = -13 (south is down

A = angle south of east
tan A = 13/5
A = 69 degrees

angle counterclockwise from x (east)
= 360 - 69 = 291
magnitude = 13