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1. MODERN GEOMETRY Sections 6.4, 6.5
Thompson

2. ANNOUNCEMENTS
Exam III on Tuesday 3/24
Covers Chapters 2 - 6

3. TEACHING PROJECT
Hippocrates’ Quadrature of the Lune (440 B.C.)
Euclid’s Proof of the Pythagorean Theorem (300 B.C.)
Archimedes Determination of Circular Area (225 B.C.)
Heron’s Formula for Triangular Area (75 A.D)
A Gem from Isaac Newton (1665)

4. TANGENT RATIO

5. SINE, COSINE RATIO

6. TRIGONOMETRIC RATIOS
hyp
opp
sin
hyp
adj
cos
adj
opp
tan
opp
hyp



sin
1
csc
adj
hyp



cos
1
sec
opp
adj



tan
1
cot



cos
sin
tan 

7. THE UNIT CIRCLE

8. FINDING TRIG RATIOS
3
4
5


9. FINDING UNKNOWN ANGLES
3
4
5


10. “SOLVING” RIGHT TRIANGLES
a
b
14

43

11. FINDING AREA
A
B
cm35

50
C
cm75

12. FORMULAS & IDENTITIES
Reciprocal Identities
Pythagorean Identities
1cossin 22
 

13. SOLVING OBLIQUE (NON-RIGHT) TRIANGLES

14. THE LAW OF SINES
Use Law of Sines when given:
•An angle and its opposite side.
•Any two angles and one side.
•Two sides and the non-included
angle.

15. THE LAW OF COSINES
Use Law of Cosines when given:
•Two sides and the included angle.
•All three sides.

16. SOLVE THE TRIANGLE

17. SOLVE THE TRIANGLE

18. SOLVE THE TRIANGLE

19. SOLVE THE TRIANGLE

20. SOLVE THE TRIANGLE

21. SOLVE THE TRIANGLE

22. CIRCLE TRIG!

23. PYTHAGOR
EAN
IDENTITIES

24. CLASSWORK / HOMEWORK
6.4
27, 45, 49, 67, 69
6.5
33, 35, 39, 47