Respuesta :

Answer:

A

Step-by-step explanation:

The median AB bisects DC at right angles ,hence BD = 4

Using Pythagoras' identity on the right triangle ABD

The square on the hypotenuse AD is equal to the sum of the squares on the other 2 sides, that is

AB² + BD² = AD², that is

AB² + 4² = 5²

AB² + 16 = 25 ( subtract 16 from both sides )

AB² = 9 ( take the square root of both sides )

AB = [tex]\sqrt{9\\}[/tex] = 3 feet → A