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ANEK [815]
3 years ago
14

I don’t understand how to proof Cpctc or answer the questions

Mathematics
1 answer:
n200080 [17]3 years ago
4 0
I think that first you need to understand what CPCTC is used for.

Let's start with the definition of congruent triangles.

Definition of congruent triangles
Two triangles are congruent if each side of one triangle is congruent to a corresponding side of the other triangle and each angle of one triangle is congruent to a corresponding angle of the other triangle.

A definition works two ways.
1) If you are told the sides and angles of one triangle are congruent to the corresponding sides and angle of a second triangle, then you can conclude the triangles are congruent.
2) If you are told the triangles are congruent, then you can conclude 6 statements of congruence, 3 for sides and 3 for angles.

Now let's see what CPCTC is and how it works.
CPCTC stands for "corresponding parts of congruent triangles are congruent."
The way it works is this. You can prove triangles congruent by knowing fewer that 6 statements of congruence. You can use ASA, SAS, AAS, SSS, etc. Once you prove two triangles congruent, then by the definition of congruent triangles, there are 6 congruent statements. That is where CPCTC comes in. Once you prove the triangles congruent, then you can conclude two corresponding sides or two corresponding angles are congruent by CPCTC. These two corresponding parts were not involved in proving the triangles congruent.

Problem 1.

Statements                                        Reasons
1. Seg. AD perp. seg. BC               1. Given
2. <ADB & <ADC are right angles     2. Def. of perp. lines
3. <ADB is congr. <ADC                 3. All right angles are congruent
4. Seg. BD is congr. seg CD           4. Given
5. Seg. AD is congr. seg. AD        5. Congruence of segments is reflexive
6. Tr. ABD is congr. tr. ACD           6. SAS
7. Seg. AB is congr. seg. AC        7. CPCTC

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Plz help before 11:59 pm I will mark brainliest
olganol [36]

Answer:

1.- 140 in²

2.- 2.25 in²

3.- 43.25 in²

4.- 7.5 in²

5. 349.75 in²

Step-by-step explanation:

4 congruent triangles mean 4 triangles same measurement

area 1 triangle=(B*H)/2=(10*7)/2=35in²

for area of the roof are 4 by area 1 triangle=4*35=140 in²

2.- area hole. Hole is a square so area Is side by side

area=1.5*1.5=2.25

3.- area front except the hole. As the side of front is isosceles trapezoide which it’s area is (B1+B2)H/2 where B1=8 in and B2=5 in and H=7 in

so arera with hole=(8+5)*7/2=45.5 in²

7 0
3 years ago
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What is the volume of the carton?<br><br> V = Bh<br><br> Area of a triangle = 1/2 x b x h
Angelina_Jolie [31]

Hi there!

\large\boxed{\text{ 10.5 in}^3}}

Begin by solving for the area of the base:

A = 1/2 (bh)

Thus:

A = 1/2(2 · 1.5) = 1.5 in²

Multiply by the depth to find the volume:

A = 1.5 × 7 = 10.5 in³

5 0
2 years ago
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13 mins left oh gees oh gosh
gavmur [86]

Answer:

I think that it is a quadratic

7 0
3 years ago
A car leaves its garage and travels for 30km on a bearing of 145, then 10 km on a bearing of 250 Calculate a) the distance trave
OverLord2011 [107]

The distance travelled from the starting point is 29 km , the bearing is 344 degree

The missing diagram is attached with the answer.

<h3>What is Bearing Angle ?</h3>

It is the horizontal angle between the object and another object.

It is given that the car starts from point travels for 30km on a bearing of 145, then 10 km on a bearing of 250

(a) the distance travelled from the starting point

It can be understood from the diagram that

To determine the distance , b is to determined4

By applying Cosine rule

b² = a² +c²-2ac cos\rm \theta

b² = 10²  +30²  - 2* 30*10 cos75

b² = 100+900 -600* 0.2588

b² = 100-155.2914

b² = 844.7

b = 29 km

Therefore the distance travelled from the starting point is 29 km.

(b) the bearing of the starting point from the car.

To determine the bearing ,

angle C has to be determined

By sine rule

sin C / c = sin B / b

sin C = sin 75 * 30 / 29

sin C = 0.9970

C = sin⁻¹ 0.9970

C = 85.59 degree

angle C = α +70 degree

α  = 15.59 degree

Bearing = 70 + 20 + 9 0 + 90+74 = 244 degree

To know more about Bearing

brainly.com/question/9214012

#SPJ1

5 0
2 years ago
Using polygon STUVW what is m angle U ?
bija089 [108]

Answer:

The m∠ U is 72°.

Step-by-step explanation:

Given:

\angle S = 90\\\angle T = 2x\\\angle U = x\\\angle V = 2x\\\angle W = 90\\

To find :

\angle U = x = ?

Solution:

The sum of the measures of the interior angles of a polygon with 'n' sides is given as

\textrm{sum of the measures of angle of a polygon with 'n' sides} = (n - 1)\times 180

Here we have n = 5 on substituting the values we get

\angle S +\angle T + \angle U +\angle V + \angle W = (5 -2)\times 180\\90 + 2x + x + 2x + 90 = 3\times 180\\5x + 180 = 540\\5x = 540-180\\5x = 360\\x = \frac{360}{5}\\x = 72

Therefore,

m∠ U is 72°.

4 0
3 years ago
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