Answer:
x = 11
BC = 23
AD = 29
EF = 26
Step-by-step explanation:
Given:
Trapezoid ABCD, having,
median = EF = 4x - 18
base BC = x + 12
base AD = 3x - 4
Required:
Part I: value of x
Part II: Length of BC, AD, and EF.
Solution:
Part I: Value of X
The median length of a trapezoid is said to be the ½ of the sum of the 2 bases of the trapezoid.
Therefore, EF = ½(BC + AD)
4x - 18 = ½((x + 12) + (3x - 4)
4x - 18 = ½(x + 12 + 3x - 4)
4x - 18 = ½(x + 3x +12 - 4)
4x - 18 = ½(4x + 8)
Multiply 2 by both sides
2(4x - 18) = 4x + 8
8x - 36 = 4x + 8
Add 36 to both sides
8x - 36 + 36 = 4x + 8 + 36
8x = 4x + 44
Subtract 4x from both sides
8x - 4x = 4x + 44 - 4x
4x = 44
Divide both sides by 4
x = 11
Part II:
BC = x + 12 = 11 + 12 = 23
AD = 3x - 4 = 3(11) - 4 = 33 - 4 = 29
EF = 4x - 18 = 4(11) - 18 = 44 - 18 = 26
