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
Alborosie
3 years ago
5

Experimentally verify sum of three angles of an triangle is 180⁰.​

Mathematics
1 answer:
svetlana [45]3 years ago
4 0

Draw line a through points A and B. Draw line b through point C and parallel to line a.

Since lines a and b are parallel, <)BAC = <)B'CA and <)ABC = <)BCA'.

It is obvious that <)B'CA + <)ACB + <)BCA' = 180 degrees.

Thus <)ABC + <)BCA + <)CAB = 180 degrees.

Lemma

If ABCD is a quadrilateral and <)CAB = <)DCA then AB and DC are parallel.

Proof

Assume to the contrary that AB and DC are not parallel.

Draw a line trough A and B and draw a line trough D and C.

These lines are not parallel so they cross at one point. Call this point E.

Notice that <)AEC is greater than 0.

Since <)CAB = <)DCA, <)CAE + <)ACE = 180 degrees.

Hence <)AEC + <)CAE + <)ACE is greater than 180 degrees.

Contradiction. This completes the proof.

Definition

Two Triangles ABC and A'B'C' are congruent if and only if

|AB| = |A'B'|, |AC| = |A'C'|, |BC| = |B'C'| and,

<)ABC = <)A'B'C', <)BCA = <)B'C'A', <)CAB = <)C'A'B'.

You might be interested in
A zoo has a circular pool for its seals. The diameter of the pool is 32 feet. Formulas Hide calculator ⇐Clear789/456*123-0.=+ Se
sveta [45]
9.85 square feet. 32/2=16 16*3.14^2=9.85
8 0
3 years ago
The scatter plot below shows what kind of trend?
Dovator [93]

the answer is b no trend

4 0
2 years ago
PLS HELP WILL MARK BRAINLIEST! NO FAKE ANSWERS!<br><br>Name the circle and find mDCF
den301095 [7]

Answer:

Step-by-step explanation:

A circle is named by its center.

Name of the circle:  Circle B

∠DCF = 90°   {angle on a semicircle is right angle}

8 0
2 years ago
Read 2 more answers
Is the following number rational or irrational?<br> √121
Aloiza [94]

Answer:

Rational

Step-by-step explanation:

Because it gives whole number which is 11

3 0
3 years ago
Read 2 more answers
Anne has 24 pencils in a box.eighteen has #2 marked on them and the 6 are marked #3.what is fraction of pencils are marked 3
Arada [10]
1/4 because 6/24 can be simplified all the way down to 1/4
6 0
2 years ago
Other questions:
  • Lila decided to make more baked goods for the bake sale she used 1/8 lb less flour to make the bread then to make the cookies. S
    12·1 answer
  • Bob has burn 300 calories in the past hour he didn't goes home and he's a candy bar that is 300 calories true or false is it an
    6·1 answer
  • Micheal has been awarded a pay rise of 4%.His salary is £ 24 492 <br> What was his apart before?
    12·1 answer
  • Please help and please show work<br>will give brainlyist
    8·2 answers
  • A laptop cost $450 more than a camera. Mr Bala paid $2400 for 2 such laptops and 1 such camera. Mr Kumar bought 1 such laptop an
    12·1 answer
  • How do you simplify (3x+1/2)+(7x-41/2)
    7·1 answer
  • one leg of a right triangle is 6.4 cm long the length of the second leg is 3.5 cm what is the length of the hypotenuse rounded t
    5·1 answer
  • A student sees a bird on top of a 12m high light pole. The student is standing 20m from the base of the pole. At what angle must
    13·1 answer
  • I need help please i will give u brainly
    7·2 answers
  • Solve the following sub 1) find the value of p,ifp +5=3
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!