Find the missing angle measure in the polygon below:
63
52
xº
989
X =

5.) 15x - 4 + 5x - 8 = 180

(The two angles are supplementary, so when added together they form a straight angle that measures 180 degrees.)

Combine Like Terms:

15x - 4 + 5x - 8 = 180

20x - 12 = 180

Add 12 on both sides:

20x - 12 = 180

       +12    +12

20x = 192

Divide by 20:

20x = 192

/20     /20

x = 9.6

Substitute for angle ABD:

15x - 4

15(9.6) - 4

144 - 4

= 140

The measure of angle ABD is 140 degrees.

Substitute for angle DBC:

5x - 8

5(9.6) - 8

48 - 8

= 40

The measure of angle DBC is 40 degrees.

2.) Area of triangle:

A = bh/2

A = 10(6.25)/2

A = 62.5/2

A = 31.25 yd^2

Area of rectangle A:

A = lw

A = 10(5)

A = 50 yd^2

Area of rectangle B:

A = lw

A = (6.5)7.5

A = 48.75 yd^2

Total Area:

31.25 + 50 + 48.75 = 130

130 yd^2

1.) Set up equation:

180 = 3.2n + 6.4n + 2.4n

180 = 12n

/12     /12

15 = n

Substitute for angle X:

3.2n = 3.2(15) = 48°

Substitute for angle Y:

6.4n = 6.4(15) = 96°

Substitute for angle Z:

2.4n = 2.4(15) = 36°