L. _____ _____. J. N. K. M. CPCTC. Be able to use CPCTC to find unknowns in congruent triangles!. Quick Review. Are these triangles congruent? By which postulate/theorem?. Oh, and what is the Reflexive Property again?.
Be able to use CPCTC to find unknowns in congruent triangles!
Are these triangles congruent? By which postulate/theorem?
Oh, and what is the Reflexive Property again?
It says something is equal to itself. EX: A A or AB AB.
Corresponding Parts of Congruent Triangles are CONGRUENT!!CPCTC
Once you have shown triangles are congruent, then you can make some CONCLUSIONS about all of the corresponding parts (_______ and __________) of those triangles!
Are the triangles congruent? By which postulate or theorem?
What other parts of the triangles are congruent by CPCTC?
If B = 3x and Y = 5x –9, find x.
3x = 5x - 9
9 = 2x
1. 1. ___________
3. 3. ___________
2. _______________ 2. Reflexive
4. _______________ 4. ___________
1. _____________________ 1. Given
2. _____________________ 2. SSS
3. _____________________ 3. ________
State why the two triangles are congruent and write the congruence statement. Also list the other pairs of parts that are congruent by CPCTC.
A geometry class is trying to find the distance across a small lake. The distances they measured are shown in the diagram. Explain how to use their measurements to find the distance across the lake.
Vertical angles are congruent.
The triangles are congruent by SAS.
The width of the lake has to be 24.5 yd by CPCTC.
A landscape architect sets up the triangles shown in the figure to find the distance JK across a pond. What is JK?
1. figure to find the distance N P; NO || MP
Given: NO || MP, N P
Prove: MN || OP
3. MO MO
6. MN || OP
2. NOM PMO
2. Alt. Int. s Thm.
3. Reflex. Prop. of
4. ∆MNO ∆OPM
5. NMO POM
6. Conv. Of Alt. Int. s Thm.
6. figure to find the distance DX BX
Given: X is the midpoint of AC . 1 2
Prove: X is the midpoint of BD.
1. X is mdpt. of AC. 1 2
2. AX = CX
2. Def. of mdpt.
3. AX CX
3. Def of
4. AXD CXB
4. Vert. s Thm.
5. ∆AXD ∆CXB
5. ASA Steps 1, 4, 5
7. Def. of
7. DX = BX
8. X is mdpt. of BD.
8. Def. of mdpt.