Cool shapes

Geometry Level 2

Given that the area of the big hexagon is 23.38 cm 2 23.38 \text{cm}^2 , what is the area of the blue region? (Give the answer in cm 2 \text{cm}^2 up to two decimal places)


The answer is 5.84.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

5 solutions

The big hexagon is composed of 6 equal triangular portions, and each of that portion consists of smallest triangular (the white one) number of 7+5+3+1 = 16 pieces.

Therefore, the big hexagon has a total number of 96 pieces.

Each blue “snow flake” portion consists of 12 pieces.

So 2 blue “snow flakes” has total area of (24/96)(23.38) = 5.845 cm2.

doesnt the big hexagon contain 8 full hexagons and 2 split half so total =10 and contains 10*6= 60 triangles. independent triangles = 12 2 blue regions = 12 +12 = 24 triangles so 60+12+24 = 96 23.38 /96 * (12+12) = 5.845 cm^2

Mohammed Ali - 6 years, 3 months ago

The desired answer is 5.84 5.84 .

Gamal Sultan
Mar 10, 2015

Let the area of one white triangle be X

The large regular hexagon is consists of 96 small triangles each of them is equal to the white one

Then

96 X = 23.38

X = 0.24354

The 2 blue region consists of 24 of such small triangle

The area of the blue region = 24 X = 24(0.24354) = 5.845

Robert Gerace
Mar 10, 2015

The white triangles have the same side length as the little hexagons. It can be seen that 4 of these side lengths make up one side of the big hexagon. Since the little hexagons are 1/4 as long, they have (1/4)^2 the area of the big hexagon.

Each of the blue stars can be thought of as a little hexagon bordered by 6 white triangles, and 6 white triangles together have area equal to one little hexagon. So each blue star is equal to 2 little hexagons, or 2/16 of the total area.

With both stars, the area is 4 * 1/16 * 23.38 = 5.845 cm^2

Victor Chen
Mar 10, 2015
  1. The hexagon can be arranged into a rectangle to find its area.
  2. Area = base * height
  3. Area = (1.5 s) * (sqrt(3) s)
  4. Area = 1.5 sqrt(3) s^2
  5. s = sqrt(Area/(1.5*sqrt(3)))
  6. s = sqrt(23.38/(1.5*sqrt(3)))
  7. s = approx. 2.999
  8. Each six pointed star is made of 12 equilateral triangles.
  9. Each side of the small triangles is equal to 1/4 of side s.
  10. ss = s/4 = 0.749
  11. Small triangle area = b*h/2
  12. area = ss * (ss*sqrt(3)/2) / 2
  13. area = 2435416
  14. area * 12 = 1 six pointed star, area * 24 = total area 15 area*12 = approx 5.84

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...