Starting from point A Tianna walks for 20 m till point C in north east direction before turning to her right. She walks 20 m again turning to her right stopping at point B. How far is point A from point B?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \(20\sqrt{2}\) m
A right turn is a turn of 90° taken from the direction she is facing at that moment:
From A she walks 20 m facing north-east and reaches C.
Facing north-east, a right turn makes her face south-east; she walks 20 m and stops at B.
The two walks meet at C at a right angle, so AB is the hypotenuse of a right triangle with both arms 20 m (Pythagoras’ theorem):
\(AB=\sqrt{20^2+20^2}=\sqrt{800}=20\sqrt{2}\) m