In an isosceles triangle, the base 0.8 dm is greater than the side. Find the sides of the triangle if its perimeter is 5.9 dm.

1) If we denote the length of the side side for x dm, then the base, which is 0.8 dm larger, will be (x + 0.8) dm. It is known that the triangle is isosceles, which means that if the perimeter is 5.9 dm, you can write the equation:
x + x + (x + 0.8) = 5.9,
3x = 5.1,
x = 1.7.
2) Accordingly, the base will be equal to:
1.7 + 0.8 = 2.5 (dm).
Answer: equal sides have a length of 1.7 in, and the base is 2.5 in.