1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Vikki [24]
3 years ago
12

Classwork 12.1 surface area

Mathematics
1 answer:
s344n2d4d5 [400]3 years ago
6 0

Answer:

6) LA = 90 units² and SA = 202 units²

7) LA = 377 units² and SA = 477.5 units²

8) LA = 208 units² and SA = 232 units²

9) LA = 455 units² and SA = 591 units²

Step-by-step explanation:

* Lets revise the rules of lateral area and surface area

- Lateral area of the solid = perimeter of its base × its height

- Surface area = lateral area + 2 × area of its base

* Now lets solve the problems

6) The solid is a rectangular prism

- Its base is a rectangle with dimensions 8 units and 7 units

- Its height is 3 units

∵ Perimeter of the rectangle = 2(L + W)

∴ Perimeter of the base = 2(8 + 7) = 2(15) = 30 units

∴ LA = 30 × 3 = 90 units²

∵ Area of the rectangle = L × W

∴ Area of the base = 8 × 7 = 56 units²

∴ SA = 90 + 2 × 56 = 90 + 112 = 202 units²

7) The solid is a cylinder

- Its base is a circle with diameter 8 units

∴ Its radius = 8 ÷ 2 = 4 units

- Its height is 15 units

∵ The perimeter of the circle is 2πr

∴ The perimeter of the base = 2π(4) = 8π

∴ LA = 8π(15) = 120π = 376.99 ≅ 377 units²

∵ The area of the circle = πr²

∴ The area of the base = π(4)² = 16π

∴ SA = 120π + 2 × 16π = 120π + 32π = 152π = 477.5 units²

6) The solid is a triangular prism

- Its base is a triangle with sides 5 , 5 , 6 units and height 4 units

- Its height is 13 units

∵ Perimeter of the triangle is the sum of the 3 sides

∴ Perimeter of the base = 5 + 5 + 6 = 16 units

∴ LA = 16 × 13 = 208 units²

∵ Area of the triangle = 1/2 × base × height

∴ Area of the base = 1/2 × 6 × 4 = 12 units²

∴ SA = 208 + 2 × 12 = 208 + 24 = 232 units²

9) The solid is a prism

- Its base is an isosceles trapezium with parallel bases 7 units and 10

 units, 2 non-parallel bases 9 units and height 8 units

- Its height is 13 units

∵ Perimeter of the trapezium is the sum of its sides

∴ Perimeter of the base = 7 + 10 + 9 + 9 = 35 units

∴ LA = 35 × 13 = 455 units²

∵ Area of the trapezium = 1/2(b1 + b2) × h

∴ Area of the base = 1/2(7 + 10) × 8 = 68 units²

∴ SA = 455 + 2 × 68 = 455 + 136 = 591 units²

You might be interested in
Deva bought 9 1/2 m of cloth for rupees 28 1/2.Samruth buys 26 1/3 m of same cloth. how much should samruth pay the shopkeeper?
likoan [24]

For this case we can make the following rule of three:

9 1/2 m --------------> 28 1/2 rupees

26 1/3 m -------------> x

From here, we clear the value of x.

We have then:

x = (\frac{26+\frac{1}{3}}{9+\frac{1}{2}}) (28+\frac{1}{2})

Rewriting we have:

x = (\frac{\frac{79}{3}}{\frac{19}{2}}) (\frac{57}{2})

x = (\frac{158}{57}) (\frac{57}{2})

x = \frac{158}{2}

x = 79

Answer:

samruth should pay 79 rupees to the shopkeeper

5 0
3 years ago
Can someone help please!<3
elena-s [515]
The equation that works for this is
y=1/7x + 0! It is parallel and goes through (0,0)
Hope this helps :)
8 0
3 years ago
Please help I don’t understand this
horrorfan [7]

Answer:

C) 17

Step-by-step explanation:

Using the rule

A^2 + B^2 = C^2

8^2 + 15^2 = x^2

64 + 225 = x^2

x^2 = 289

x= _/-289

x = 17

3 0
3 years ago
Suppose that, from measurements in a microscope, you determine that a certain bacterium covers an area of 1.50μm2. Convert this
galben [10]
1 m = 1 x 10⁶ μm
1 m² = (1 x 10⁶)² μm²
1 m² = 1 x 10¹² μm²

area = 1.5 / 1 x 10¹²  m²
Area = 1.5 x 10⁻¹² m²
7 0
3 years ago
Solve the following equation 3x+7=10
serious [3.7K]

Answer: x=1

Step-by-step explanation:

8 0
2 years ago
Read 2 more answers
Other questions:
  • 2 angles of a triangle are the same size. the 3rd is 3 times as large as the 1st​
    11·1 answer
  • The longest side of an acute triangle measures 30 inches. The two remaining sides are congruent, but their length is unknown. Wh
    11·2 answers
  • Does the point (0,4) make either equations y=-2x and y=x+3 true? Explain.
    11·1 answer
  • What is the vertical intercept of x-y=2
    5·1 answer
  • I need help finding the pattern!!!!
    6·1 answer
  • -6n + 3= 45<br><br>how do solve this? I need help showing my work<br>​
    12·1 answer
  • A particular metal has a density of 25g/cm cubed. Calculate the mass of 178cm cubed of this metal.​
    15·1 answer
  • ANSWER QUICKLY! Brainliest if you get the correct answer
    9·2 answers
  • Solve for k<br><br> 10/3 = k/9<br><br> K =
    7·2 answers
  • (16x^3)^3/4 Express in simplest radical form.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!