Find the perimeter and area of a rectangle with a length of 5 cm and a diagonal of 13 cm

Use the Pythagorean Theorem to find the other side length, as the triangle formed by the 5cm and the 13cm side is a right triangle.
5^2 + ?^2 = 13^2
25 + ?^2 = 169
?^2 = 169 - 25
?^2 = 144
? = 12
Now you know the rectangle is 5cm by 12cm, you can find the area by multiplying the two, and the perimeter by doubling both then adding.
Final
area = 5 * 12 = 60cm^2
perimeter = 5*2 + 12*2 = 34cm 
Hope I helped :)