Answer: 294√3
Explanation:
1) The described hexagon has these featrues:
a) 6 congruent equilateral triangles whose side lengths measure 14
b) height of each triangle = apotema = a
c) the area of each triangle is base × a / 2 = 14 × a / 2 = 7a
2) a is one leg of a right triangle whose other leg is 14 / 2 = 7, and the hypotenuse is 14.
3) Then you can use Pythagorean theorem fo find a:
14² = 7² + a² ⇒ a² = 14² - 7² = 147 ⇒ a = √ 147 = 7√3
4) Therefore, the area of one triangle is: 14 × 7√3 / 2 = 49√3
5) And the area of the hexagon is 6 times that: 6 × 49√3 = 294√3
<h2>9.</h2><h3>Given</h3>
<h3>Find</h3>
- linear approximation to the volume when the radius increases 0.4 cm
<h3>Solution</h3>
The equation for volume of a sphere is
... V = (4/3)π·r³
Differentiating gives
... dV = 4π·r²·dr
Filling in the given numbers gives
... change in volume ≈ 4π·(15 cm)²·(0.4 cm)
... = 360π cm³ ≈ 1130.97 cm³ . . . . . . volume of layer 4mm thick
<h2>11.</h2><h3>Given</h3>
- an x by x by 2x cuboid with surface area 129.6 cm²
- rate of change of x is 0.01 cm/s
<h3>Find</h3>
<h3>Solution</h3>
The area is that of two cubes of dimension x joined together. The area of each such cube is 6x², but the two joined faces don't count in the external surface area. Thus the area of the cuboid is 10x².
The volume of the cuboid is that of two cubes joined, so is 2x³. Then the rate of change of volume is
... dV/dt = (d/dt)(2x³) = 6x²·dx/dt
We know x² = A/10, where A is the area of the cuboid, so the rate of change of volume is ...
... dV/dt = (6/10)A·dx/dt = 0.6·(129.6 cm²)(0.01 cm/s)
... dV/dt = 0.7776 cm³/s
24.652 = 24 65/100
24 65/100 is your answer
hope this helps
Answer:
d.39%
Step-by-step explanation:
Loki told me
But really, 39% should be correct
Answer:
120
Step-by-step explanation:
All the interior angles in a regular hexagon are 120 degrees.
