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:
C or d
Step-by-step explanation:
Answer:
B- doubling a cube
D- trisecting any angle
Step-by-step explanation:
APEX
We can solve this problem using the binomial distribution. A binomial distribution<span> can be thought of as a success or failure outcome in an experiment or survey that is repeated multiple times.
</span>Probability function of binomial distribution has the following form:

p represents the probability of each choice we want. k is the number of choices we want and n is the total number of choices.
In our case p=0.85, k=5 and n=6.
We can now calculate the answer:

The probability is 39%.
.
He can make 32 sandwiches. Since he uses 1/8 pound of cheese for each sandwich, he can make 8 sandwiches using 1 pound of cheese (1/8 x 8 = 1). Now that you know he can make 8 sandwiches with 1 pound of cheese, multiply 8 (this is the sandwiches) by 4 (pounds of cheese).