The perimeter of an isosceles trapezoid is 28 in and the ratio of lengths of its bases is 5: 3. find the lengths of the sides of the trapezoid if its diagonal bisects the angle at the longer base.

The measurements are:
b₁ = 8.4 inches; b₂ = 14 inches; leg₁ = 2.8 inches; leg₂ = 2.8 inches

Let x = length of base and leg

The formula for perimeter of isosceles trapezoid is P = b₁ + b₂ + 2(leg)
Where: b = base

       P = b₁ + b₂ + 2(leg)
     28 = 3x + 5x + 2(x)
     28 = 8x + 2x
28/10 = 10x/10
    2.8 = x

Now, substitute the values:
       P = b₁ + b₂ + 2(leg)
     28 = 3(2.8) + 5(2.8) + 2(2.8)
     28 = 8.4 + 14 + 5.6
     28 = 28

Hence the measurements are:
b₁ = 8.4 inches; b₂ = 14 inches; leg₁ = 2.8 inches; leg₂ = 2.8 inches

Google it that might work