Answer:
80 cm
Step-by-step explanation:
The diagonals divide the rhombus into four congruent triangles. The height of each triangle is 18/2 = 9, and the hypotenuse is 41. Using Pythagorean theorem, the width of each triangle is:
c² = a² + b²
41² = 9² + x²
x = 40
Therefore, the longer diagonal is 2×40 = 80.
