Geometry: An Interactive Journey to Mastery

Pitfall
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these formulas look the way they do, and you will then be able to reconstruct them in your mind as you
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1. Find exact values of sin 75 , cos 75 , and tan 75. ͼ௘5HFDOOWKDWtan x sincos^ xx .· ̧ ̧¹


2. Consider Figure 18.2.
   D௘ͽ 8VHWULJRQRPHWU\WR¿QGWKHYDOXHRId.
   E௘ͽ )LQGd using the Pythagorean theorem.
   F௘ͽ $UHWKHWZRDQVZHUVWKHVDPH"


3. Consider the rectangular box shown in Figure 18.3.
   D௘ͽ :KDWLVWKHOHQJWKRIAB?
   E௘ͽ 7RRQHGHFLPDOSODFHZKDWLVWKHPHDVXUHRIDQJOHCAB?


4. :KDWLVWKHPHDVXUHRIWKHODUJHVWDQJOHLQDLVRVFHOHVWULDQJOH"


5. :KDWLVWKHPHDVXUHRIWKHVPDOOHVWDQJOHLQDULJKWWULDQJOH"

Problems

31.7

d 21.2

Figure 18.2

C

A

B

12

7

5

Figure 18.3