The statement is true.
If the sides of the triangle are \(5x\), \(12x\), and \(13x\) units respectively, then: \[ (5x)^2 + (12x)^2 = 25x^2 + 144x^2 = 169x^2 = (13x)^2 \] \[ \because\ \text{The sum of the squares of two sides equals the square of the third side,} \] Therefore, the triangle must be a right-angled triangle.