Answer:
the second one is the answer
(x+(x+2)+(x+4)+(x+6))=4x+12=212
x+x+x+x(2+4+6)=4x+12=212
4x (2+4+6)=4x+12=212
4x(6+6)=4x+12=212
12+4x=4x+12=212
<u>-12 -12 -12</u>
4x=4x=200
<u>/4 /4 /4</u>
<u>x=x=50</u>
<u>x=50</u>
0.6n = n + 31.8
0.6n - n = 31.8
-0.4n = 31.8
n = 31.8 / -0.4
n = -79.5
<h3>Given</h3>
1) Trapezoid BEAR with bases 11.5 and 6.5 and height 8.5, all in cm.
2) Regular pentagon PENTA with side lengths 9 m
<h3>Find</h3>
The area of each figure, rounded to the nearest integer
<h3>Solution</h3>
1) The area of a trapezoid is given by
... A = (1/2)(b1 +b2)h
... A = (1/2)(11.5 +6.5)·(8.5) = 76.5 ≈ 77
The area of BEAR is about 77 cm².
2) The conventional formula for the area of a regular polygon makes use of its perimeter and the length of the apothem. For an n-sided polygon with side length s, the perimeter is p = n·s. The length of the apothem is found using trigonometry to be a = (s/2)/tan(180°/n). Then the area is ...
... A = (1/2)ap
... A = (1/2)(s/(2tan(180°/n)))(ns)
... A = (n/4)s²/tan(180°/n)
We have a polygon with s=9 and n=5, so its area is
... A = (5/4)·9²/tan(36°) ≈ 139.36
The area of PENTA is about 139 m².
