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
-3x + 7y = -16 . . . (1)
-9x + 5y = 16 . . . .(2)
(1) x 3 => -9x + 21y = -48 . . . (3)
(2) - (3) => -16y = 64 . . . (4)
Required equivalent system of equations is
-9x + 5y = 16
-16y = 64
Answer: It would be the first one, 0.001 kilometers per meter.
Step-by-step explanation: is 1,000 meters is equal to 1 kilometer, you would have to move the decimal on each until one is at one and the other is at 0.001. This would leave you with the first answer. Hope this helps!
Answer:
Well, at least you improved. But maybe you should use another source besides brainly for your tests. Sometimes people put the wrong answers just to get points.
I hope you do better next time! Good luck!!
Answer:
Be an GH
Step-by-step explanation: