Respuesta :

Answer:

AD = 230

Step-by-step explanation:

here, we want to find the measure it AD

To do this, we need the value of x firstly

To get this, we are going to use the trapezoid midpoint theorem

The theorem is that the sum of the two parallel sides of a trapezoid when divided by 2 will give the middle point length of the trapezoid

Applying this:

1/2{30x-10+ 30x + 28} = 31x + 1

2(31x + 1) = 60x+ 18

divide both sides by 2

31x + 1 = 30x + 9

31x -30x = 9-1

x = 8

But;

AD = 30x-10

AD = 30(8)-10

AD = 240-10

AD = 230