Answer:
28
Step-by-step explanation:
Since, Sum of triangle is equal to 180°
180 = 2x + 50 + 3x - 10
180 = 5x + 40
180 - 40 = 5x
140 = 5x
140/5 = x
28 = x
1. area of a pentagon when 1 side is x is

so if perimiter is 100 then one side is 100/5 or 20
area will be

≈<span>688.2 square yards
2. area of a hexagon when 1 side is length x is

so if permiter is 100 then length of one side is 100/6 or about 16.666666666666
the area will be

≈721.7 square yards
3. area of a regular octagon with side lenghts x is

so if 8 sides then side length of each is 100/8 or 12.5
area will be

≈754.4 square yards
octagon wil have most space
you can tell because the more sides it has, the more it gets to a circle and the more area it encloses with a given perimiter
</span>
<span>We'll do two by two,
1.4 – 5.5= -4.1
</span><span>– 1.73 + 1.8= 0.07
Leaving </span><span>– 1.09,
You get </span>
=-4.1+<span> 0.07- 1.09
=-4.03-1.09
=-5.12</span>
The triangles are similar because two angles have the same measurements
Subtract 6.7 from 20. This is 13.3. Divide 13.3/5 is 2.66. That is the answer