AREA OF BASIC PLANE FIGURES | GRADE 6 — Transcript

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1. 0:02[Music]
2. 0:10area of basic plane figures
3. 0:14hello there students welcome back to my
4. 0:17classroom
5. 0:18for today's lesson you are going to
6. 0:20learn how to
7. 0:21solve the area of square rectangle
8. 0:24triangle circle and semicircle
9. 0:28let us start let's take a look at this
10. 0:31first example we have here a square
11. 0:34whose side measures four centimeters
12. 0:38now let us turtle mean its area
13. 0:41wait do you know what area means
14. 0:44[Music]
15. 0:47area is the number square units needed
16. 0:49to cover the surface of a plane
17. 0:51figure a square unit is a square
18. 0:55whose each side measures one unit
19. 0:58[Music]
20. 1:01if its side measure one centimeter its
21. 1:04area will be
22. 1:05one square centimeter if it's one
23. 1:08kilometer
24. 1:09it will be one square kilometer
25. 1:13or if it's one inch it will be called
26. 1:16one square inch and so on
27. 1:21now to determine the area of a certain
28. 1:23plane figure
29. 1:24we just simply need to count the number
30. 1:27of square unit
31. 1:28it covers now let's try and go back to
32. 1:32our example
33. 1:34again we have your square whose side
34. 1:37measure
35. 1:374 centimeter it means that it has 4
36. 1:411 centimeters now let's count
37. 1:44one two three
38. 1:48and four as well on the other side we
39. 1:52have four centimeters so it means
40. 1:54it has four one centimeter so let us
41. 1:57count
42. 1:57one two three and
43. 2:01four now we can see that we already have
44. 2:04some square
45. 2:05units now again to determine its area we
46. 2:08just simply need to count the number of
47. 2:10square units it
48. 2:11covers now let us count 1
49. 2:142 3 4 5
50. 2:186 7 8 9
51. 2:2110 11 12 13
52. 2:2414 15 and 16 centimeters squared
53. 2:28it means that its area is 16 squares
54. 2:31centimeters now here we can observe that
55. 2:34if we multiply 4
56. 2:36centimeters by 4 centimeters
57. 2:39we will get the area which is 16 square
58. 2:42centimeters it means that the formula to
59. 2:45get the area of a square
60. 2:47is side times side or s
61. 2:50times s or s squared
62. 2:53now let's try this formula to our next
63. 2:56example
64. 2:57again we have here a square but this
65. 3:00time each
66. 3:01side measures nine decimeter again the
67. 3:04formula for the area of square is side
68. 3:07times side or s squared so here the
69. 3:10measure of the side is
70. 3:119 decimeters so that will be 9
71. 3:14decimeters
72. 3:14times 9 decimeters if we multiply that
73. 3:18that will be 81 square decimeters
74. 3:21and that is the area of this square
75. 3:25wonderful now let's go and have another
76. 3:28example
77. 3:29this time we have our rectangle whose
78. 3:32length
79. 3:32measures seven meters it means that it
80. 3:35has
81. 3:36seven one meters now let us count one
82. 3:39two three four
83. 3:43five six and seven
84. 3:46while it's sweet measure three meters
85. 3:50it means that it has three one meters so
86. 3:53let's count
87. 3:54one two and three
88. 3:57now we already have some square units
89. 4:00now to get its area let us count them
90. 4:09now we have 21 square meters and that
91. 4:12is its area now we can observe that if
92. 4:16we multiply
93. 4:177 meters to 3 meters we will get its
94. 4:21area which is 21 square meters
95. 4:24it means that if we multiply the length
96. 4:28and the width we are going to get its
97. 4:31area
98. 4:32therefore the formula for the area of
99. 4:34rectangle
100. 4:35is length times width
101. 4:40now let's try this formula for our next
102. 4:42example
103. 4:44again we have here our rectangle whose
104. 4:47length measures
105. 4:48nine meters and width measures
106. 4:51four meters now let us salt
107. 4:54we have the formula for the area of
108. 4:56rectangle which is length times sweep
109. 4:59now let's multiply 9 meters to 4 meters
110. 5:03[Music]
111. 5:04and that will be 36 square meters great
112. 5:10job
113. 5:12now we have here another example this
114. 5:15time we have
115. 5:16a triangle whose one side measures six
116. 5:20meters so that means it has six one
117. 5:23meter
118. 5:23so let us count one two
119. 5:27three four five
120. 5:30and six while the other side measures
121. 5:34three meters it means that it has three
122. 5:37one meter
123. 5:38now let us count one
124. 5:41two and three now if we
125. 5:45count the number of square units that we
126. 5:47have here
127. 5:48that will be eighteen square meters but
128. 5:51we can see
129. 5:52that we form a rectangle
130. 5:55and 18 square meters is the area
131. 5:58of the rectangle form but we are only
132. 6:02looking for the area of the triangle
133. 6:04as we can observe the triangle is the
134. 6:07half
135. 6:08of the rectangle it means that if we
136. 6:11divide
137. 6:12our area which is 18 square meters into
138. 6:15two
139. 6:16that would be nine square meters which
140. 6:19is the area of the triangle
141. 6:22we can observe if we multiply the
142. 6:25measures of each side which is
143. 6:273 meters and 6 meters
144. 6:30and divide it to 2 we will get the area
145. 6:33of the triangle which is
146. 6:359 square meters therefore
147. 6:38the formula for the area of triangle
148. 6:40would be
149. 6:43base times the height
150. 6:46divided by two or b
151. 6:50times h divided by two
152. 6:53now let's try this formula and solve
153. 6:56another
154. 6:56example here we have another triangle
155. 7:01whose height measures 8 meters
156. 7:04while the base measures 5 meters
157. 7:07again the formula for the triangle is
158. 7:10base times height
159. 7:11divided by 2. now let us solve
160. 7:15we have 5 meters times 8 meters
161. 7:19divided by 2. 5 meters times 8 meters is
162. 7:24great job is 40 square meters
163. 7:28now let's divide it into two and that
164. 7:30will be
165. 7:3120 square meters and that
166. 7:34is the area of the triangle
167. 7:37wonderful now let's have another example
168. 7:42this time we have a circle to get the
169. 7:45area of the circle
170. 7:47we are going to use the formula pi r
171. 7:50squared here the volume file we are
172. 7:54going to use
173. 7:55is 3.40 now the r stands for
174. 7:59radius the radius is the half
175. 8:02of the diameter which is the 4
176. 8:06inches therefore the half of the
177. 8:08diameter
178. 8:10which is 4 inches is two
179. 8:13inches but here we need to get the
180. 8:16squared
181. 8:16of the radius this means that we are
182. 8:19going to multiply it by itself
183. 8:21two times so that will be two inches
184. 8:25times two inches now let the sole
185. 8:28two inches times two inches is four
186. 8:31square
187. 8:32inches now let's multiply three point
188. 8:34fourteen
189. 8:35by four square inches
190. 8:39and that will be 12.56 square
191. 8:42inches and that is the area of this
192. 8:45circle
193. 8:47great job now let's move on to our last
194. 8:51example
195. 8:52this time we have a semi-circle
196. 8:55a semi-circle is half of a circle
197. 8:58now to get the area of the semicircle we
198. 9:01just simply need to divide the pi
199. 9:04r squared by two again the value pilot
200. 9:07we are going to use
201. 9:08is 3.14 and the radius here
202. 9:12is half of the diameter which is 4
203. 9:15inches
204. 9:15and the half of the 4 inches is 2
205. 9:19inches so that will be 2 inches times
206. 9:22two inches divided by two
207. 9:25now let us solve we have 12.56 square
208. 9:28inches
209. 9:29divided by two and that would be
210. 9:336.28 square inches
211. 9:36and that is the area of this semi-circle
212. 9:41wonderful you made it this far
213. 9:44students now here are the things that
214. 9:46you learn
215. 9:48today
216. 9:53[Music]
217. 10:08[Music]
218. 10:14you