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3 years ago

Help please? I don’t get math at all

Mathematics

1 answer:

blagie [28]3 years ago

3 0

Answer:

DE=15 and AB=6

Step-by-step explanation:

Both Triangles are Similar. When looking at the length of AC, it is 3x smaller than CE. So we know that the triangle ABC is 3x smaller than CDE. Since we know that we can see that DE is 15 since it is 3x Larger than 5. We also know that AB is 6 since it is 3x smaller than 18

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Solve the oblique triangle where side a has length 10 cm, side c has length 12 cm, and angle beta has measure thirty degrees. Ro

Ugo [173]

Answer:

$Side\ B = 6.0$

$\alpha = 56.3$

$\theta = 93.7$

Step-by-step explanation:

Given

Let the three sides be represented with A, B, C

Let the angles be represented with $\alpha, \beta, \theta$

[See Attachment for Triangle]

$A = 10cm$

$C = 12cm$

$\beta = 30$

What the question is to calculate the third length (Side B) and the other 2 angles ( $\alpha\ and\ \theta$ )

Solving for Side B;

When two angles of a triangle are known, the third side is calculated as thus;

$B^2 = A^2 + C^2 - 2ABCos\beta$

Substitute: $A = 10$ , $C =12$ ; $\beta = 30$

$B^2 = 10^2 + 12^2 - 2 * 10 * 12 *Cos30$

$B^2 = 100 + 144 - 240*0.86602540378$

$B^2 = 100 + 144 - 207.846096907$

$B^2 = 36.153903093$

Take Square root of both sides

$\sqrt{B^2} = \sqrt{36.153903093}$

$B = \sqrt{36.153903093}$

$B = 6.0128115797$

$B = 6.0$ <em>(Approximated)</em>

Calculating Angle $\alpha$

$A^2 = B^2 + C^2 - 2BCCos\alpha$

Substitute: $A = 10$ , $C =12$ ; $B = 6$

$10^2 = 6^2 + 12^2 - 2 * 6 * 12 *Cos\alpha$

$100 = 36 + 144 - 144 *Cos\alpha$

$100 = 180 - 144 *Cos\alpha$

Subtract 180 from both sides

$100 - 180 = 180 - 180 - 144 *Cos\alpha$

$-80 = - 144 *Cos\alpha$

Divide both sides by -144

$\frac{-80}{-144} = \frac{- 144 *Cos\alpha}{-144}$

$\frac{-80}{-144} = Cos\alpha$

$0.5555556 = Cos\alpha$

Take arccos of both sides

$Cos^{-1}(0.5555556) = Cos^{-1}(Cos\alpha)$

$Cos^{-1}(0.5555556) = \alpha$

$56.25098078 = \alpha$

$\alpha = 56.3$ <em>(Approximated)</em>

Calculating $\theta$

Sum of angles in a triangle = 180

Hence;

$\alpha + \beta + \theta = 180$

$30 + 56.3 + \theta = 180$

$86.3 + \theta = 180$

Make $\theta$ the subject of formula

$\theta = 180 - 86.3$

$\theta = 93.7$

5 0

3 years ago

Joe is 5 years older than Sydney. The sum of their ages is 45. What is Sydney’s age?

sweet-ann [11.9K]

Answer:

20 years old

Step-by-step explanation:

Joe = J

Sydney = S

J = 5 + S

J + S = 45

Substitute

5 + S + S = 45

Add

5 + 2S = 45

Subtract 5 from both sides of the equation

2S = 40

Divide both sides of the equation by 2

S = 20

Sydney is 20 years old

Hope this helps :)

8 0

3 years ago

How many years is tween 1844 to2015

STatiana [176]

To find the number of years between 1844 to 2015 you have to subtract.

Lets say that x is the # of years in between 1844 and 2015

Then we have:
$\sf{2015 - 1844 =x}$

After doing the subtraction using a calculator or a pencil and paper, you get that:

$\huge{\boxed{\bf{x=171}}}$

So 171 years have passed from 1844 to reach to 2015.

4 0

3 years ago

Read 2 more answers

Write the equation of a Line that is perpendicular to y=5/2x+3 and passes

koban [17]

Answer:

Step-by-step explanation:

Slope of perpendicular lines = -1

y = 5/2x + 3

$m_{1}=\frac{5}{2}\\\\m_{1}*m_{2}=-1\\\\$

$m_{2}=$ -1 ÷ $m_{1}$

= $-1*\frac{2}{5}=\frac{-2}{5}$

(-3 , -5)

Equation of the required line: y - y₁ = m(x -x₁)

y - [5] = $\frac{-2}{5}(x - [-3])\\$

$y+5=\frac{-2}{5}x + 3*\frac{-2}{5}\\\\y+5=\frac{-2}{5}x-\frac{6}{5}\\\\ y =\frac{-2}{5}x-\frac{6}{5}-5\\\\ y = \frac{-2}{5}x-\frac{6}{5}-\frac{5*5}{1*5}\\\\ y = \frac{-2}{5}x-\frac{6}{5}-\frac{25}{5}\\\\\\ y=\frac{-2}{5}x-\frac{31}{5}$

5 0

3 years ago

2 4 8 16 what is the rule and the sixth number in the sequence answers

aleksklad [387]

The sequence is incrementing by
${2}^{n}$
Therefore, the sixth number is
${2}^{6}$
Which is 64.

7 0

3 years ago