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3 years ago

Can someone pls help for brainlest

Mathematics

1 answer:

gregori [183]3 years ago

5 0

Diameter of the semicircle = 10 km.

Explanation: perimeter of semicircle = 1 2

the circumference + diameter Given: perimeter of semicircle = 25.7 k m

Circumference of circle with radius r = 2 π r where 2 r = diameter ⇒ 25.7 = 22 π r + 2 r ⇒ 25.7 = π r + 2 r = r ( π + 2 ) ⇒ 25.7 = r ( 3.14 + 2 ) = r ( 5.14 ) ⇒ r = =5m ⇒d i a m e t e r = 2 r = 10 k m

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Find the Value of Sin A rounded to the nearest hundredth, if necessary.

leonid [27]

Step-by-step explanation:

In trigonometry, the law of sines is an equation that relates the length of the sides of a triangle (any type of triangle) to the sines of its angles. This is expressed mathematically as

$\displaystyle\frac{a}{\sin \alpha} \ = \ \displaystyle\frac{b}{\sin \beta} \ = \ \displaystyle\frac{c}{\sin \gamma}$ ,

where $a$ , $b$ , and $c$ are the lengths of the sides of the triangle and $\alpha$ , $\beta$ , and $\gamma$ are the opposite angles (as shown in the figure below). Likewise, the law is sometimes written as it reciprocals,

$\displaystyle\frac{\sin \alpha}{a} \ = \ \displaystyle\frac{\sin \beta}{b} \ = \ \displaystyle\frac{\sin \gamma}{c}$ .

Therefore,

$\displaystyle\frac{\sin A}{BC} \ = \ \displaystyle\frac{\sin B}{AC} \\ \\ \\ \sin A \ = \ \displaystyle\frac{\sin B \ \times \ BC}{AC} \\ \\ \\\sin A \ = \ \displaystyle\frac{\sin \left(90^{\circ}\right) \ \times \ \sqrt{\left(10\right)^{2} \ - \ \left(\sqrt{78}\right)^{2}}}{10} \\ \\ \\ \sin A \ = \ \dsiplaystyle\frac{\sqrt{22}}{10} \\ \\ \\ \sin A \ = \ 0.47 \ \ \ \ (\text{nearest hundredth})$

Alternatively, you can solve this question using the definition of the trigonometric function sine. For the angle $\theta$ in the figure below,

$\sin \theta \ = \ \displaystyle\frac{\text{opposite}}{\text{hypothenuse}}$ .

Therefore,

$\sin A \ = \ \displaystyle\frac{BC}{AC} \\ \\ \\ \sin A \ = \ \displaystyle\frac{\sqrt{\left(10\right)^{2} \ - \ \left(\sqrt{78}\right)^{2}}}{10} \\ \\ \\ \sin A \ = \ \displaystyle\frac{\sqrt{22}}{10} \\ \\ \\ \sin A \ = \ 0.47 \ \ \ \ (\text{nearest hundredth})$

8 0

3 years ago

Pls help I will mark u as braniliest !!

Zepler [3.9K]

Answer:

CW, CT, MP, LW, MW

Step-by-step explanation:

THIS IS ALL THE COMBINATION SHE CHOOSED I HOPE THIS ANSWER HELPED YOU.

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3 years ago

How do you determine if polygons are similar?

OleMash [197]

Answer:

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3 years ago

An exterminator must treat the perimeter of a house for insects. If the house is 90 feet long and 30 feet wide, what is the tota

Anika [276]

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4 years ago

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KonstantinChe [14]

If you would like to know which pair of measurements is not equivalent, you can calculate this using the following steps:

1 yard = 3 feet
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Not equivalent: <span>3 miles, 15,480 feet.</span>

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3 years ago