The sides of a triangle are in the ratio 3:4:5. The triangle is:
Answer: B
Let the sides be 3x, 4x, and 5x. We check if they form a Pythagorean triplet.
(3x)² + (4x)² = 9x² + 16x² = 25x².
(5x)² = 25x².
Since (3x)² + (4x)² = (5x)², the sides satisfy the Pythagorean theorem. Therefore, the triangle is a right-angled triangle.