16. Find the area of a regular hexagon with a side length of 4.
From Quiz Geometry
Answer:
24 times the square root of 3
First, use the theorem to find the area of a regular polygon: A = 1/2 * A * P, where A = the apothem and P = the perimeter of the figure.
Since it's a hexagon, it has six sides, which are all 4 (so the perimeter is 6 * 4 = 24). Put this into the equation and you now have A = 1/2 * a * 24. You can now reduce this to A = 12 * a, or A = 12a. This is because 24 * 1/2 = 12. In hexagons, you can set up 6 equilateral triangles in its interior, with sides of 4. Divide any of these in half, and you are given a 30-60-90 triangle, whose side lengths are proportional 1:square root of 3:2, where 1 is the short leg, 2 is the hypotenuse, and the square root of 3 is the long leg. You know this is a 30-60-90 triangle because 2, the shorter leg, is half of 4, the hypotenuse. Then you can multiply the shorter leg, 2, by the square root of 3 to get 2 times the square root of 3 for the apothem. This is because of the proportion mentioned above. Now, plug this into the equation A=12*2 times the square root of 3. Your answer, after simplifying, is 24 times the square root of 3. Not too complicated.