4. EF is the median of trapezoid ABCD. B
X +12
с
E
4x-18
F
3x-4
A
Part I: Solve for x. Show your work. (4 points)

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

x = central angle apc = measure of minor arc ac

the two angles x and 30 add to 180, so x+30 = 180 and x = 180-30 = 150. the measure of minor arc ac is 150 degrees.

what we need to do from here is find the circumference and then multiply it by x/360 since there are 360 degrees in a circle. in this case, x = 150, so x/360 = 150/360 = 15/36 = 5/12. the shortest distance along the curve from a to c is 5/12 of the distance around the entire circle (aka circumference)

c = circumference

c = pi*d

c = pi*24

c = 24pi

now multiply this by 5/12 to get

distance along minor arc ac = (5/12)*(circumference)

distance along minor arc ac = (5/12)*(24pi)

distance along minor arc ac = 10pi

the formula you can use is

l = (x/360)*pi*d

with

l = length of minor arc

x = central angle

d = diameter

which essentially is the steps we took though a bit differently.

in the math equation 8 x 7 = 56, the 8 and the 7 are both factors of 56, since in this lesson we will use square tiles to figure out the factors of a whole find as many different arrays as you can, but follow one important rule: all the rows must have the i can make two rows of nine, so 2 and 9 are both factors of 18.

step-by-step explanation: