Not sure how to answer question 4

Mathematics

2 answers:

laiz [17]3 years ago

8 0

D = 86
Because its the nearest degree to 90 as you see < BAC seems to be 90

drek231 [11]3 years ago

5 0

Answer:

<em>Option D is correct</em>

Step-by-step explanation:

Applying the cosine theorem for triangle ABC, you would have:

cos (angle BAC) = (BA^2 + CA^2 - BC^2)/(2*BA*CA)

= (10^2 + 18^2 - 20^2)/(2*10*18)

= 24/360

=> angle BAC = ~86 deg

Hope this helps!

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puteri [66]

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8 0

3 years ago

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The volumes of two spheres are in a ratio of 1:8 what is the eatio rafi

Agata [3.3K]

Remark
I take it that you want to know the ratio of the radii. If this is not correct, leave a comment below my answer.

You could do this by giving the spheres a definite volume, like 1 and 8 and then solve for r for one of them and then use the other sphere to find it's radius. It is not exactly the best way, and if you are going to to a physics class you want to be doing this using cancellation.

Step One
Set up the Ratio for the volumes.

$\frac{V_1}{V_2} = \frac{1}{8}$

Step Two
Setup the equation for V1/V2 using the definition for a sphere. V = 4/3 pi r^3

$\dfrac{1}{8} = \frac{ \frac{4}{3} \pi( r_1)^3 }{ \frac{4}{3} \pi( r_2)^3 }$

Step Three
Cancel the 4/3 and pi on the top and bottom of the fractions on the right.

You are left with 1/8 = (r1)^3/ (r2)^3

Step Four
Take the cube root of both sides.
cube root 1/8 = 1/2

Cube root of (r1)^3 = r1
Cube root of (r2)^3 = r2

Step Five
Answer
$\frac{r_1}{r_2} = \frac{1}{2}$ Answer <<<<<<<

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3 years ago

What is the volume of the square pyramid shown below?

NemiM [27]

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