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Sloan [31]
3 years ago
13

Find the area of of a regular octagon with side length 20 cm.

Mathematics
1 answer:
Alla [95]3 years ago
8 0

A=2(1+\sqrt{2})a^2=2·(1+\sqrt{2})·20^2≈1931.37085cm²

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the cylinder has radius 4√3 and hight h. the total surface area of the cylinder is 56π√6. find the exact value of h giving the a
Arte-miy333 [17]

The area of the cylinder is a function of its height (h) and radius, (\mathbf{4\sqrt 3})

The exact value of h is: \mathbf{7\sqrt 2- 4\sqrt 3}

The given parameters are:

\mathbf{Area =56\pi\sqrt 6}

\mathbf{r=4\sqrt 3}

The surface area of a cylinder is calculated as:

\mathbf{Area = 2\pi rh + 2\pi r^2}

Substitute values for Area

\mathbf{56\pi\sqrt 6= 2\pi rh + 2\pi r^2}

Divide through by pi

\mathbf{56\sqrt 6= 2 rh + 2r^2}

Substitute value for r

\mathbf{56\sqrt 6= 2 (4\sqrt 3)h + 2(4\sqrt 3)^2}

\mathbf{56\sqrt 6= 8h\sqrt 3 + 2\times 48}

\mathbf{56\sqrt 6= 8h\sqrt 3 + 96}

Collect like terms

\mathbf{8h\sqrt 3 = 56\sqrt 6- 96}

Make h the subject

\mathbf{h = \frac{56\sqrt 6}{8\sqrt 3}- \frac{96}{8\sqrt 3}}

\mathbf{h = 7\sqrt 2- \frac{12}{\sqrt 3}}

Rationalize

\mathbf{h = 7\sqrt 2- \frac{12\sqrt 3}{3}}

\mathbf{h = 7\sqrt 2- 4\sqrt 3}

Hence, the exact value of h is: \mathbf{7\sqrt 2- 4\sqrt 3}

Read more about surface areas t:

brainly.com/question/25131428

5 0
2 years ago
How to find the square root
stepladder [879]

Answer:

Step-by-step explanationPaso 1

1 Si el radicando tiene más de dos cifras separamos las cifras en grupos de dos, empezando por la derec2 Calculamos la raíz cuadrada entera o exacta, del primer grupo de cifras por la izquierda, ha.3 El cuadrado de la raíz obtenida 2 (es decir 4) se resta al primer grupo de cifras que aparecen en el radicando Bajamos el siguiente grupo de cifras del radicando, separando del número formado (492) la primera cifra a la derecha (2) y dividiendo lo que resta entre el doble de la raíz 2, es decir 2(2)=4.  5En otra fila debajo de la raíz colocamos el doble de la misma (4). A continuación, se coloca el cociente que se obtenga (9) . Y luego el número obtenido (49) se multiplica por dicho cociente (9). Después, se resta (441) a la cantidad operable (492) del radicando.  El cociente obtenido (9) es la segunda cifra de la raíz, quedando (29) Bajamos el siguiente par de cifras y repetimos los pasos anteriores.

 Prueba de la raíz cuadrada. Para que el resultado sea correcto, se tiene que cumplir:

 

.

8 0
3 years ago
Solve the equation x2 = 10.
MatroZZZ [7]

Answer:

\large\boxed{x=-\sqrt{10}\ or\ x=\sqrt{10}}

Step-by-step explanation:

x^2=10\iff x=\pm\sqrt{10}

8 0
3 years ago
Name the segment parallel to the given segment for #2
Svetlanka [38]

YZ ║ XT

RS ║ XZ

XY ║ TS

I am not a professional, I am simply using prior knowledge!

Note- It would mean the world to me if you could mark me brainliest!

5 0
3 years ago
Find the GCE.<br> 10rs, 35rst
lukranit [14]
The GCE of 10 and 35 is 5
7 0
3 years ago
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