The foot of a ladder is 6m from the base of an electric pole. The top of the ladder rest against the pole at a…

Analyze the question: The pole stands vertically on the ground, so the pole, the ground and the ladder form a right-angled triangle.

• Base (foot of ladder to pole) = 6 m
• Height (where the ladder touches the pole) = 8 m
• The ladder is the slanted side, called the hypotenuse.

Concept: Pythagoras' theorem says that in a right-angled triangle:

c² = a² + b²

where c is the hypotenuse, and a and b are the other two sides.

Solution:

Let the ladder's length be L.

L² = 6² + 8² L² = 36 + 64 L² = 100 L = √100 L = 10 m

Answer: The ladder is 10 m long, which is option C.

Tip: Memorize the common Pythagorean triples: (3, 4, 5), (5, 12, 13), (8, 15, 17). Here 6 and 8 are double 3 and 4, so the hypotenuse is double 5, which is 10. Spotting these triples saves time in JAMB, WASSCE and NECO.