A tree is 8km due south of a building. Kofi is standing 8km west of the tree. How far is Kofi from the building?
Answer Details
We can use the Pythagorean theorem to solve this problem. Kofi is 8 km west of the tree, which means he is directly north of the building. We can draw a right-angled triangle with the building at the southeast corner, the tree at the southwest corner, and Kofi at the north corner. The distance between the building and the tree is the hypotenuse of the right-angled triangle, and the distance between Kofi and the tree is one of the legs.
Using the Pythagorean theorem, we can find the length of the hypotenuse:
hypotenuse² = leg₁² + leg₂²
In this case, leg₁ is 8 km (the distance between Kofi and the tree), and leg₂ is 8 km (the distance between the tree and the building):
hypotenuse² = 8² + 8²
hypotenuse² = 128
hypotenuse = √128
hypotenuse = 8√2
Therefore, Kofi is 8√2 km away from the building. Option C, 8√2km, is the correct answer.