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
Sholpan [36]
2 years ago
5

4. What is the circumference of a circle whose area is 81π cm squared?

Mathematics
2 answers:
vichka [17]2 years ago
7 0
Area = pi*r^2
Circumference = 2pi*r

Step 1: find the radius from area
81pi=pi*r^2
81=r^2
9=r

Step 2: plug in radius to the circumference equation

Circumference = 2pi*r

18pi is the answer, otherwise know as 56.52 as well.
pogonyaev2 years ago
3 0

Step-by-step explanation:

Let us assume R be the radius of circle We know that, area of circle = πR2 81πr2 = πR2 R = √81 r R = 9r Circumference = 2 πr = 2 π (9r) = 18πr

You might be interested in
Write each phrase as an algebraic expression.<br> 16 seconds faster than Aya’s time.
Liula [17]
Aya’s time + 16 seconds
X+16
8 0
3 years ago
Type the correct answer in the box.<br><br><br> In this triangle cosA/cosB= blank
Elina [12.6K]

Answer:

1

Step-by-step explanation:

A triangle is a polygon with three sides and three angles. The types of triangles are scalene triangle, equilateral triangle, right angled triangle and obtuse triangle.  

Trigonometric functions are used to show the relationship between the angles of a triangles and the sides of the triangle. For a right angled triangle, the ratio of the sides can be gotten using trigonometric functions such as:

cosθ = adjacent/hypotenuse, sinθ = opposite/hypotenuse, tanθ = opposite/adjacent

Given the right angle triangle:

cos(A) = adjacent / hypotenuse = 3 / 4.24

cos(A) = 3 / 4.25

cos(B) = adjacent / hypotenuse = 3 / 4.24

cos(B) = 3 / 4.24

cos(A) / cos(B) = (3 / 4.24) ÷ (3 / 4.24) = 1

cos(A) / cos(B) = 1

3 0
3 years ago
The radius of a circle is 21 in. What is the precise distance around the circle?
Afina-wow [57]

Answer:

IT IS REALLY 31

Step-by-step explanation:

7 0
2 years ago
I don’t understand help
Yuliya22 [10]

Answer:

a)-4x+7=9×3

-4x=27-7

x=-20/4

x=-5

b)49r-55r=-52+10

-6r=-42

r=-42/6

r=7

c)-6m+8m-2m=-1-5+6

2m-2m=0

0=0

4 0
2 years ago
A store sells 7 different types of envelopes and 6 different types of postage stamps. How many different combinations are there
solong [7]
Answer

42

Explanation

Let’s say:

Set of envelopes: {a,b,c,d,e,f,g}

Set of postage stamps: {1,2,3,4,5,6}

For an envelope you can have:

1a 2a 3a 4a 5a 6a (6 different combinations)

This applies to all 7 different types of envelopes.

Therefore 7 • 6 = 42
5 0
3 years ago
Other questions:
  • How long will it take to drive 30 miles going 15 mph?
    15·2 answers
  • Help please I don’t understand this at all??
    5·1 answer
  • Which of the following is true about the graphs below?
    9·1 answer
  • How do you reduce the ratio 4:80
    14·1 answer
  • Is 2 And 22 linear or nonlinear?
    9·2 answers
  • What is 35% of 60? just had to be 20 words
    11·2 answers
  • Ms. Allen asked each of her 30 students to select their favorite type of music. How many students chose Rock 1/3 chose hip hop 1
    12·1 answer
  • Write the below algebraic expression<br> in words<br> 3x+ (x)=10<br> 2
    15·1 answer
  • Parallel lines m and n are cut by the transversal line t prove &lt;1 and &lt;4 are supplementary move options to the boxes to co
    6·1 answer
  • Answer these 3 pleaseeeeeeeeeeeeeeeeeeeeeeeeee
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!