The <em>total</em> area of all six faces of the tunnel is
square centimeters.
<h2>Procedure - Surface area of a tunnel for a toy train</h2>
The surface area of the solid (
) used to represent the tunnel for a toy train is the sum of its six faces (two <em>semicircular</em> sections, inner <em>semicircular</em> arc section, outer <em>semicircular</em> arc section, two rectangles).
<h3>Determination of the surface area of the tunnel based on information of the diagram</h3>
We calculate the surface area as following:
![A = 2\cdot \frac{\pi}{2} \cdot [(10\,cm)^{2}-(8\,cm)^{2}] + \pi\cdot (8\,cm)\cdot (30\,cm) + \pi\cdot (10\,cm)\cdot (30\,cm) + 2\cdot (2\,cm)\cdot (30\,cm)](https://tex.z-dn.net/?f=A%20%3D%202%5Ccdot%20%5Cfrac%7B%5Cpi%7D%7B2%7D%20%5Ccdot%20%5B%2810%5C%2Ccm%29%5E%7B2%7D-%288%5C%2Ccm%29%5E%7B2%7D%5D%20%2B%20%5Cpi%5Ccdot%20%288%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29%20%2B%20%5Cpi%5Ccdot%20%2810%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29%20%2B%202%5Ccdot%20%282%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29)

The <em>total</em> area of all six faces of the tunnel is
square centimeters. 
To learn more on surface areas, we kindly invite to check this verified question: brainly.com/question/2835293
Answer:
Step-by-step explanation:
Square
The side length of the square = 8 cm
The area of the square = s^2
The area of the square = 8^2 = 64
Circle
r = d/2
r = 8/2
r = 4
Area of the circle = pi r^2
Area of the circle = 3.14 * 16
Area of the circle = 50.24
Shaded Area
Area of the Shaded area = area Square - Area Circle
= 64 - 40.24
= 23.76
The external angle is suplementary to the internal angle close to it. We also know that the sum of all the internal angles of the triangle are equal to 180 degrees, this means that the angle "a" is suplementary to the sum of the angles "b" and "c". Through this logic, we can conclude that since:

Then we can conclude that:

Therefore the statement is true, the exterior angle is equal to the sum of its remote interior angles.
Let's use an example:
On this example, the external angle is 120 degrees, therefore the sum of the remote interior angles must also be equal to that. Let's try:

The sum of the remote interior angles is equal to the external angle.
Answer:
65 liters
Step-by-step explanation:
11/5=2.2
143/2.2=65