Direction & Distance
Learning Objectives
- Understand the fundamental concepts of Direction & Distance
- Apply key formulas and techniques to solve problems
- Practice with exam-level questions to build speed and accuracy
Key Concepts
What is Direction & Distance?
Direction and Distance is a high-scoring topic in SSC CGL Tier 1 reasoning. Questions test your ability to track movement on a plane using cardinal directions and compute the final position relative to the start. Every SSC CGL paper has 1–3 questions from this chapter.
The 4+4 Directions Compass
The compass has four cardinal directions: North (N), South (S), East (E), West (W) — 90° apart from each other — and four intercardinal (ordinal) directions: North-East (NE), North-West (NW), South-East (SE), South-West (SW) — each 45° from the adjacent cardinal direction. The full circle is 360°.
SSC Tip: Always draw a small compass rose (N↑) on your rough diagram before plotting paths. This prevents confusion when turning.
a) East b) West c) South d) North
Direction Changes — Left / Right / Turn Around
Right Turn: Facing N→E, E→S, S→W, W→N (clockwise shift).
Left Turn: Facing N→W, W→S, S→E, E→N (anticlockwise shift).
Turn Around (about turn): 180° rotation — N→S, E→W, etc.
SSC Shortcut: Use a reference table on your rough sheet: if facing X and turning Y, the new direction is… Memorise the cyclic order N-E-S-W.
a) North b) South c) East d) West
a) NE b) NW c) SE d) SW
Pythagoras Distance & Common Triplets
When a person moves in two perpendicular directions, the straight-line displacement is found using the Pythagoras theorem:
d² = (Net East-West)² + (Net North-South)²
SSC Favourite Triplets:
- 3–4–5: 3²+4²=5² (9+16=25)
- 5–12–13: 5²+12²=13² (25+144=169)
- 8–15–17: 8²+15²=17² (64+225=289)
- 7–24–25: 7²+24²=25² (49+576=625)
- 9–40–41: 9²+40²=41² (81+1600=1681)
If the net E-W and N-S distances match a Pythagorean triplet, the displacement is the hypotenuse. This saves calculation time.
a) 4 km b) 5 km c) 7 km d) 1 km
a) 7 m b) 13 m c) 17 m d) 15 m
a) 15 m b) 16 m c) 17 m d) 23 m
Displacement vs Distance
Distance is the total path length travelled (sum of all individual steps). Displacement is the straight-line distance from the starting point to the ending point, along with the direction. SSC CGL usually asks for displacement, not total distance. Read the question carefully.
a) 20 m, 0 m b) 0 m, 20 m c) 10 m, 10 m d) 20 m, 20 m
Shadow Problems
Shadow direction depends on the sun’s position. Three key cases for SSC CGL:
- Sunrise (Morning): Sun in the East. Shadows fall towards the West.
- Sunset (Evening): Sun in the West. Shadows fall towards the East.
- Noon: Sun directly overhead. No shadow is formed.
Shadow Rule: If a person is facing the sun, their shadow falls behind them. If the sun is on their left/right, the shadow falls to the right/left respectively. The shadow is always opposite to the sun’s direction.
a) Left b) Right c) Front d) Back
a) North b) South c) East d) West
a) Maximum b) Minimum (zero) c) Moderate d) Cannot determine
Multiple Person Movement
When two or more persons move from a common starting point, track each person’s coordinates independently, then find the distance between the final points using the distance formula: d = √[(x₁−x₂)² + (y₁−y₂)²]
a) 10 m b) 14 m c) 2√37 m d) 20 m
a) P b) Q c) Both equally close d) Cannot determine
SSC Shortcut Techniques
1. Path Tracing Method: Draw the path as arrows on a rough grid. Label distances. Connect start and end with a straight line. Measure/calculate using Pythagoras. This visual method prevents mistakes.
2. Sign Convention Table:
- East = +x, West = −x
- North = +y, South = −y
- Net x = sum of all East-West movements
- Net y = sum of all North-South movements
- Displacement = √(x² + y²)
3. Shadow Rule: Morning → sun East → shadow West. Evening → sun West → shadow East. Noon → no shadow.
4. Direction Change Table: If facing North: left=W, right=E, about turn=S. If facing East: left=N, right=S, about turn=W. If facing South: left=E, right=W, about turn=N. If facing West: left=S, right=N, about turn=E.
a) 5 m East b) 5 m North c) Origin d) 5 m West
a) 5√10 m b) 5√13 m c) 10 m d) 25 m
a) North b) South c) East d) West
Advanced Examples
a) 10 m East b) 10 m West c) 50 m East d) 30 m North
a) North b) South c) East d) West
a) 25 m b) 26 m c) 13 m d) 20 m
a) 20√2 m b) 20 m c) 10√5 m d) 0 m
a) A b) B c) C d) All four
a) North b) South c) East d) West
a) √13 m b) √17 m c) 13 m d) 17 m
a) Origin b) 5 m N c) 5 m E d) 10 m NE