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3 years ago

PLEASE find SA Find the surface area to the nearest tenth. (Only round on the very last step). SA =

Mathematics

1 answer:

Dafna11 [192]3 years ago

3 0

Answer:

885.2m²

Step-by-step explanation:

a is the side length of the square at the base

h is the height of the pyramid

Given

a = 18m

Get the height using the pythagoras theorem

h² =18²-9²

h² = 324 - 81

h² = 243

h = √243

h = 15.5884m

Area of the triangle = 1/2 * 18 * 15.5884

Area of the triangle = 9 * 15.5884

Area of the triangle = 140.2956m²

Area of the 4 triangles = 4(140.2956)

Area of the 4 triangles = 561.1824m²

Base area = 18 * 18

Base area = 324m²

Total surface area = Base area + Area of the 4 triangles

Total surface area = 324 + 561.1824

Total surface area = 885.1824

Total surface area = 885.2m² (to the nearest tenth)

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A master painter can paint 110 square yards of surface area with a roller in 1 hour, while his apprentice can paint 85 square fe

7nadin3 [17]

The apprentice needs 6.25 hours to complete the job using the brush

<h3><u>Solution:</u></h3>

Given, A master painter can paint 110 square yards of surface area with a roller in 1 hour

$\text { Then, his rate of painting }=110 \text { yard }^{2}$

We know that 1 yard = 3 feet

$=110 \times(1 \text { yard })^{2}=110 \times(3 \text { feet })^{2}=110 \times 9 \text { feet }^{2}=990 \text { square feet. }$

While his apprentice can paint 85 square feet of surface area per hour with a brush

Together they are painting a building with a surface area of 5100 square feet.

After painting for $4\frac{1}{4}$ hours , the master painter lets the apprentice Finish the job.

Now, they worked for $4\frac{1}{4}$ hours

Then, area painted = area painted by master + area painted by apprentice

$\text { Area painted }=990 \text { square feet per hour } \times 4 \frac{1}{4} \text { hours }+85 \text { square feet per hour } \times 4 \frac{1}{4} \text { hours }$

$\text { Area painted }=990 \times \frac{4 \times 4+1}{4}+85 \times \frac{4 \times 4+1}{4}$

$\begin{array}{l}{\text { Area painted }=990 \times \frac{17}{4}+85 \times \frac{17}{4}=(990+85) \times \frac{17}{4}} \\\\ {\text { Area painted }=1075 \times \frac{17}{4}=4568.75 \text { square feet. }}\end{array}$

Now, the remaining area to be painted = total area – painted area

Area to be painted = 5100 – 4568.75 = 531.25

So, apprentice has to paint 531.25 square feet alone.

$\text { Then, time required }=\frac{\text { area to be painted }}{\text { his rate of painting }}$

$=\frac{531.25}{85}=6.25$

Hence, the apprentice needs 6.25 hours to complete the job

7 0

4 years ago

Morita works in a florist shop and makes flower arrangements. She puts 10 flowers in each vase and 2/10 of the flowers are daisi

Delvig [45]

First, find how many flowers are in 4 arrangements: 10*4=40

You can set this up as a proportion:
²/₁₀ = x/₄₀

You can also just multiply 2 daisies by 4 arrangements.

8 daisies

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4 years ago

Which set of side lengths form a right triangle?

Luba_88 [7]

53 48 24 should be the answer but im not 100% sure

6 0

3 years ago

Read 2 more answers

Macar+acar+car+ar+r=VACAR urgent please

USPshnik [31]

1 Simplify exponent
ma2cr+acar+car+ar+r=vacar

2 Simplify exponent
ma2cr+a2cr+car+ar+r=vacar

3 Factor out the common term r
r(ma2c+a2c+ca+a+1)=vacar

4 Cancel r on both sides
ma2c+a2c+ca+a+1=vaca

5 Subtract a2c from both sides
ma2c+ca+a+1=vaca−a2c

6 Factor out the common term ca
ma2c+ca+a+1=ca(va−a)

7 Subtract ca from both sides
ma2c+a+1=ca(va−a)−ca

8 Factor out the common term ca
ma2c+a+1=ca(va−a−(1))

9 Subtract a from both sides
ma2c+1=ca(va−a−1)−a

10 Factor out the common term a
ma2c+1=a(c(va−a−1)−1)

11 Subtract 1 from both sides
ma2c=a(c(va−a−1)−1)−1

12 Divide both sides by a2
mc=a(c(va−a−1)−1)−1a2

13 Divide both sides by c
m=a(c(va−a−1)−1)−1a2c

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3 years ago

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Anuta_ua [19.1K]

Answer:

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4 years ago