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
This is the work and the answer is 4/23 or (in decimal form) 0.17391304
Answer:
the "negative solution" is -3
Step-by-step explanation:
Represent the number by n.
Then n^2 - 24 = 5n
We rewrite this in standard quadratic form:
n^2 - 5n - 24 = 0
This factors as follows; (n + 3)(n - 8) = 0
The roots are n = -3 and n = 8. Thus, the "negative solution" is -3
Answer:
3/1
Step-by-step explanation:
Using the similarity statement, ∠A corresponds with ∠D; ∠B corresponds with ∠E; and ∠C corresponds with ∠F.
The only angle of triangle DEF we have is ∠E, which is 7. This corresponds with ∠B; this makes the scale factor of ABC to DEF
21/7 = 3/1.
