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p. 352. In the figure, [///] BAC =50度, AB = CD [---]AB. Find [///]BCD.[///] : http://www.flickr.com/photos/29635386@N06/3794573226/ [---] : http://www.flickr.com/photos/29635386@N06/3794573230/ Figure : http://www.flickr.com/photos/29635386@N06/3750951293/ 3. In the figure, ABCDEF is a regular... 顯示更多 p. 35 2. In the figure, [///] BAC =50度, AB = CD [---]AB. Find [///]BCD. [///] : http://www.flickr.com/photos/29635386@N06/3794573226/ [---] : http://www.flickr.com/photos/29635386@N06/3794573230/ Figure : http://www.flickr.com/photos/29635386@N06/3750951293/ 3. In the figure, ABCDEF is a regular hexagon. Find x. Figure : http://www.flickr.com/photos/29635386@N06/3751741882/ 4. Each interior angle of a regular n-sided polygon is 144度.Find n. 5. Five interior angles of a hexagon are 90度, 100度, 110度, 135度 and 140度. Find the sixth angle.

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2. In the figure, [///] BAC =50度, AB = CD [---]AB. Find [///]BCD. [///]ABC=(180-50)/2 {/base./s isos.triangle } =65 [///]BCD=180-65-90 (/ sum of triangle) =25 3.In the figure, ABCDEF is a regular hexagon. Find x. [///]EFA={(6-2)*180}/6 {多邊形內角和} forgot english = = =120 [///]EFD=(180-120)/2 {/base./s isos.triangle } =30 x=[///]EFA-2[///]EFD=120-2*30 =60 4. Each interior angle of a regular n-sided polygon is 144度.Find n. {(n-2)(180)}/n=144 n=10 5. Five interior angles of a hexagon are 90度, 100度, 110度, 135度 and 140度. Find the sixth angle. (6-2)(180)-(90+100+110+135+140) =145 So the sixth angle is 145