A rectangle has a side that is 6,2cm and a diagonal that is 12,5cm. calculate the perimeter of the rectangle

1. Assign the known values: one side of the rectangle is a = 6.2\, \text{cm} and the diagonal is d = 12.5\, \text{cm}.
2. Use the Pythagorean theorem to find the other side b:
d^2 = a^2 + b^2
12.5^2 = 6.2^2 + b^2
156.25 = 38.44 + b^2
b^2 = 156.25 - 38.44
b^2 = 117.81
b = \sqrt{117.81}
b \approx 10.85 \, \text{cm}.
3. Calculate the perimeter P of the rectangle:
P = 2a + 2b
P = 2(6.2) + 2(10.85)
P = 12.4 + 21.7
P = 34.1 \, \text{cm}.