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4 years ago

Need help with geometry

Mathematics

1 answer:

JulsSmile [24]4 years ago

7 0

Answer:

The surface area is $305.9\ ft^{2}$

Step-by-step explanation:

we know that

The surface area of the square pyramid is equal to

$SA=b^{2}+4[\frac{1}{2}bh]$

where

b is the length side of the square base

h is the height of the lateral triangular face

we have

$b=10\ ft$

Applying Pythagoras Theorem find the value of h

$h^{2}=9^{2}+(10/2)^{2}$

$h^{2}=81+25$

$h=\sqrt{106}\ ft$

substitute in the formula

$SA=10^{2}+4[\frac{1}{2}(10)(\sqrt{106})]=305.9\ ft^{2}$

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Determine which statements are true in the set of real numbers3. (Select all that apply.) (a) Two lines parallel to a third line

sashaice [31]

Answer:

(a) True

(b) False

(d) False

(e) False

(f) True

(g) False

(h) True

(i) True

(k) True

Step-by-step explanation:

(a) Two lines parallel to a third line are parallel

True

(b) Two lines perpendicular to a third line are parallel

Only for lines on the same plane

Therefore, false

True

(d) Two planes perpendicular to a third plane are parallel

The two planes can be at an angle to each other and so intersect

Therefore, false

(e) Two lines parallel to a plane are parallel

Where the two lines are on a plane parallel to the first plane but the lines are not themselves parallel to each other they intersect

Therefore, false

(f) Two lines perpendicular to a plane are parallel

True

(g) Two planes parallel to a line are parallel

Where the planes are not parallel to each other, they will intersect

Therefore, false

(h) Two planes perpendicular to a line are parallel

True

(i) Two planes either intersect or are parallel

True

(k) A plane and a line either intersect or are parallel

True.

4 0

3 years ago

Helped me please please

Aleksandr [31]

D is the correct answer

8 0

3 years ago

Three friends each have some ribbon. Carol has 54 inches of ribbon, Tino has 10.5 feet of ribbon, and

zzz [600]

Answer:

1800 inches, 150 feet, and 50 yards

Step-by-step explanation:

First, lets start in inches. multiply 45 by 3, to get 135 feet, and add that with 10.5 to get 145.5 feet. multiply that by 12 to get 1746 inches, and add 54 to that to get 1800 inches. divided that by 12 to get 150, and divided 150 by 3 to get 50.

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3 years ago

Please help! The radius of a sphere is claimed to be 3.0 inches, correct to within 0.01 inch. Use linear approximation to estima

Vilka [71]

Answer:

0,36π inches³ or simply 1.13 inches³

Step-by-step explanation:

In this case, first, we need to calculate the volume of the sphere with the formula:

V = 4πr³/3

Replacing the data we have:

V = 4π(3)³/3

V = 36 in³

Now that we have the volume we need to calculate the resulting error. In this case, using linear approximation we have to use the derivates of V and r, so we have the following:

If V = 4πr³/3

Then the derivate of V (dV) would be:

dV = 4π*3*r²/3 dr

Where dr is the error of radius so:

dV = 4π*r² dr

Solving for dV:

dV = 4*3.14*(3)²*(0.01)

dV = 1.13 in³

So at the end, we just report the volume of the sphere as

V = 36 ± 1 in³

dV =

3 0

3 years ago

Find the national number between 1/2 and 1/3

Mnenie [13.5K]

Answer:

1/2 and 1/3

LCM of 2,3=6

1/2=1/2×3/3=3/6

1/3=1/3×2/2=2/6

The six rational number

3/6=3/6×10/10=30/60

2/6=2/6×10/10=20/60

20/60,[21/60,22/60,23/60,24/60,25/60,26/60]....30/60.

1/2 and 1/3

LCM of 2,3=6

1/2=1/2×3/3=3/6

1/3=1/3×2/2=2/6

The six rational number

3/6=3/6×10/10=30/60

2/6=2/6×10/10=20/60

20/60,[21/60,22/60,23/60,24/60,25/60,26/60]....30/60.

Mark me brainliest plz ❤️

7 0

3 years ago

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