DF=3x+1, DE~=EF, DE=x+5.

The perimeter is 31.
Find x, DE, and DF.

To find the values of x, DE, and DF, we need to use the given information and solve the equations step by step.

1. The equation for the perimeter is given as 31. In a triangle, the perimeter is the sum of the lengths of all three sides. In this case, we have DE, EF, and DF as the sides.

DE + EF + DF = 31 (equation 1)

2. We are also given that DE is approximately equal to EF, or DE ~= EF. This means that DE and EF have almost the same length, implying that they are equal. So we can represent DE and EF as DE = EF.

DE = EF (equation 2)

3. The equation for DF is given as DF = 3x + 1.

DF = 3x + 1 (equation 3)

4. The equation for DE is given as DE = x + 5.

DE = x + 5 (equation 4)

Now, let's solve the equations to find the values of x, DE, and DF.

Since DE = EF (from equation 2), we can substitute DE with EF in equation 1:

EF + EF + DF = 31

2EF + DF = 31 (equation 5)

Substitute the expressions for DF (from equation 3) and DE (from equation 4) in equation 5:

2(x+5) + (3x+1) = 31

2x + 10 + 3x + 1 = 31

Combine like terms:

5x + 11 = 31

Subtract 11 from both sides:

5x = 20

Divide both sides by 5:

x = 4

Now that we have the value of x, we can substitute it into equations 3 and 4 to find DE and DF:

DE = x + 5

DE = 4 + 5

DE = 9

DF = 3x + 1

DF = 3(4) + 1

DF = 12 + 1

DF = 13

So the values of x, DE, and DF are x = 4, DE = 9, and DF = 13.