Solution:
Note that:
- 2(3x) + 2(x - 1) = 28
- Side lengths of rectangle: 3x, 3x, x - 1, x - 1
Solving the equation:
- 2(3x) + 2(x - 1) = 28
- => 6x + 2x - 2 = 28
- => 8x - 2 = 28
- => 8x = 30
- => x = 30/8 = 3.75
Substitute the values into the side lengths to find out their measures.
- 3x, 3x, x - 1, and x - 1
- => 3(3.75), 3(3.75), 3.75 - 1, 3.75 - 1
- => 11.25, 11.25, 2.75, 2.75
The length of the shortest side is 2.75 units.