3. (x + 1)/4 = 3 / 6
x + 1 = 3/6 x 4 = 2
x = 1
Scale factor = 6 / 4 = 1.5
Ratio of perimeters = 2 : 3
4. x / 21 = 20 / 15
x = 20 / 15 x 21 = 28
Scale factor = 20 / 15 = 4/3
Ratio of perimeters = 3 : 4
Answer:

Step-by-step explanation:
we know that
The area of a regular hexagon is the same that the area of 6 equilateral triangles
The area of 6 equilateral triangles applying the law of sines is equal to
![A=6[\frac{1}{2}b^2sin(60^o)]](https://tex.z-dn.net/?f=A%3D6%5B%5Cfrac%7B1%7D%7B2%7Db%5E2sin%2860%5Eo%29%5D)
where
b is the length side of the regular hexagon
we have

substitute
![A=6[\frac{1}{2}(10)^2sin(60^o)]](https://tex.z-dn.net/?f=A%3D6%5B%5Cfrac%7B1%7D%7B2%7D%2810%29%5E2sin%2860%5Eo%29%5D)

No because when you do square root 65 it then equals <span>8.0622577483.</span>
According to the identity if a+b+c=0
then a3+b3+c3=3abc
a3+b3+c3/abc=3
a2*a/bc*a+b2*b/ca*b+c2*c/ab*c=3
cancel a,b,c in all the fraction then you get
<span>a²/bc+b²/ca+c²/ab=3.
</span>hence proved