Question

ABC is an isosceles triangle right-angled at C. Then 2AC² is equal to ______.

Options

• BC²

• AC²

• AC² − BC²

• AB²

Answer 1

ABC is an isosceles triangle right-angled at C. Then 2AC² is equal to AB².

Explanation:

By applying Pythagoras’ theorem to right-angled triangle ΔABC where ∠C = 90°, we have AB² = AC² + BC². Since the triangle is isosceles, AC = BC, which allows us to substitute BC with AC to get AB² = AC² + AC² = 2AC².