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
Answer:
$620 every year
Step-by-step explanation:
Since the question didn't specify how long she would have to save for, let's just assume that it's one year. There are 52 weeks in a year which is $520, and on her birthday she would have an extra $100, so every year she saves $620 in total.
Answer:
The median is 26
Step-by-step explanation:
A "median" is equivalent to, when the terms are arranged in the proper order, whichever term is in the "middle".
So- first, arrange the terms in ascending order.
[22, 22, 23, 23, 29, 29, 29, 31]
There are an even number- eight- terms in total, so we will take the average of the two "middle" terms.
(29+23)/2; 29 and 23 are the "middle" terms, and there are two of them.
(52)/2 = 26
Therefore, the median is 26.
I hope this helped! :)