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
LenKa [72]
3 years ago
15

Paper rectangle ABCD is folded in such a way that the fold passes through point B, and so A coincides with point H where H ∈ CD.

BK is the folding line where K ∈ AD. m∠BKD = 120°. If BK = 28 cm, find BC.
Mathematics
1 answer:
aivan3 [116]3 years ago
5 0

The answer is BC = 38.22 cm.

<u>Step-by-step explanation</u>:

We have, ∠BKD = 120° ,BK = 28 cm, Draw a perpendicular from point K on BC let it intersect at point M.  In right angled ΔBMK, ∠BKM=30° and BK = 28 cm

sin30° = perpendicular/hypotenuse

1/2 = BM/BK

1/2 = BM/28

BM= 14 cm

Now , In right angled ΔBMK ,

cos30° = base/hypotenuse

√3/2 = MK/28

MK = 14√3 = 24.22 cm

KMCD is a square  MK = MC = 24.22 cm

also, BC = BM + MC , putting values of BM & MC we get :

BC = 14 cm + 24.22 cm

BC = 38.22 cm.

You might be interested in
What is the area of the sector of the circle below, if the radius is 5 m. and the central angle &lt; AOB measures 88 °. (round a
MariettaO [177]

Answer:

b 19.2

Step-by-step explanation:

a = \pir^{2} for a circle.  We do not want to find the area for a whole circle.  We only want to find the area for part of a circle.  a hole circle is 360 degrees.

a = \frac{88}{360}\pir^{2}

a = \frac{88}{360}\pi(5^{2})

a = 19.2 rounded.

8 0
1 year ago
Read 2 more answers
Kate is going to purchase a coat for $38, pants for $45, and 2 pairs of shoes for $34 each. if she has $180 to spend how much mo
likoan [24]
She would have 20 dollars left over. take the amount of money she has then add up all of the cost of the stuff she will buy then subtract.
5 0
3 years ago
100 POINTS PRE-CALCULUS
Sonja [21]

Answer:

not sure for the 1st one but pretty sure 2nd one is B

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
For a population with µ = 80 and σ = 20, the distribution of sample means based on n = 16 will have an expected value of _______
wlad13 [49]

Answer:

calculate the number of atom in 3 mol helium

7 0
1 year ago
PLEASE HELP
KIM [24]
A20-a18=a1+19d-a1-17d=2d =281-97 so d=92
3 0
3 years ago
Other questions:
  • A jewelry store marked up the price of its well-known necklace. The new price of the necklace is $250, which is 125% of the orig
    11·2 answers
  • Assume that you don’t know any kind of longhand method of division. Explain how you can use reasoning to calculate 495 ÷ 35
    10·1 answer
  • Find all roots (zeros) please show work!!
    10·1 answer
  • Write this numeral in scientific notation.<br> 2,000,004
    12·2 answers
  • How many times does 3 go into 36
    5·2 answers
  • How many observations does this dot plot represent?
    12·2 answers
  • F(n)=-4n-3; find f(-1)
    5·1 answer
  • 1) Which expression is equal to
    7·1 answer
  • This table shows the linear relationship of the water level in a tank and time.
    12·1 answer
  • Find x helpppppppppppp​
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!