question_subject:
question_exam:
stats:
keywords:
In this question, R initially faces east and walks straight for 4 km. Then, R turns left and walks another 3 km. After that, R turns left again and walks 4 km.
To determine how far R is from the starting point, we can consider the displacements made in each direction. Since R turns left twice, it essentially moves in a counter-clockwise direction.
The initial displacement of 4 km east is offset by a subsequent displacement of 4 km west (when R turns left for the first time). This means that R is back to its starting point horizontally.
Next, R moves 3 km in the opposite direction of its initial displacement, which means it is moving north. Finally, R turns left and moves 4 km in the opposite direction again, which means it is moving west.
So, R ends up 3 km north and 4 km west from its starting point. This establishes a right-angled triangle with legs measuring 3 km and 4 km. By using the Pythagorean theorem (a^2 + b^2 = c^2) to find the hypotenuse (c), which is the distance from R to the starting point, we get:
c^2 = 3^2