Geometry: An Interactive Journey to Mastery

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E௘ͽ :KDWLVWKHDUHDRIWKHFLUFOHZLWKHTXDWLRQͼ௘xí௘ͽ^2 + y^2 = 17? What is the circumference of this circle?
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D௘ͽ :HQHHGʌU^2 = 16. This gives r (^4) S.
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The circumference of this circle is 217,S DQGLWVDUHDLVʌ
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Find the area of the shaded region shown in )LJXUH.
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We can compute the area of the shaded region by computing the area of the
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area of sector = 36060 SS5.^2 256
area of equilateral triangle = 22415 ˜˜  (^552) ̈ ̧§·©¹^2 25 3.
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Thus, the area of the shaded region is^2564 S25 3 square units.

5 60°

Figure 22.1

5 60°

60°

Figure 22.2

5 30° 30°

(^52)
Figure 22.3