哪个图形包含的面积更大:边长为 2 厘米的正方形 边长为 3 厘米和 2 厘米的矩形 边长为 4 厘米、高 2 厘米的三角形?
正方形是一个有四个边和四个角的封闭二维图形。所有四个边的长度相等且彼此平行。
正方形是四边形,其中:
- 对边是平行的。
- 四边相等。
- 所有角度均为 90°。
正方形的面积
正方形的面积是包围在其边界内的空间。它由其两侧中任何一条的乘积给出,并以平方单位表示。通过公式,我们有,
正方形的面积 = 边 × 边
让我们假设正方形的边等于 S。
所以,
Area = S2.
三角形的面积
三角形是包含在三个边内的二维图形,其长度可能相等,也可能不相等。该区域被认为是包含在三个边内的空间。三角形的高度将顶点连接到第三边底部的中点。现在。
让我们假设 h 是三角形的高度,b 是三角形的底,
所以,
面积 = 1/2 × 底 × 高
= 1/2 × b × h
矩形的面积
矩形的面积是包围在其边界内的空间。它由任何长度和宽度的乘积给出,并以平方单位表示。通过公式,我们有,
矩形的面积 = 长 x 宽
让我们假设矩形的长度等于 l,b 是宽度。
所以,
Area = length × breadth.
哪个图形包含的面积更大:边长为 2 厘米的正方形 边长为 3 厘米和 2 厘米的矩形 边长为 4 厘米、高 2 厘米的三角形?
解决方案:
According to the formulae computed above, we have,
Area of a square = (side)2.
Here
Side = 2 cm
Therefore, Area = 22 cm2
= 4 cm2 …..I
Area of rectangle = length x breadth
We have,
length = 3 cm
breadth = 2 cm
Therefore, Area = 3 × 2 cm2
= 6 cm2 …..II
And, area of triangle = 1/2 × Base × Height
= 1/2 × 4 × 2 cm2
= 4 cm2…. III
Therefore, on comparing, we have,
Area of rectangle > Area of square = Area of triangle
类似问题
问题1:计算哪个形状包围的面积更大;
边长为 10 m 的正方形,
长 11 m 宽 10 m 的矩形,
高 20 m 底边 11 m 的三角形
解决方案:
As we know that
I. Area of square = Side × Side
Area of square = Side2
Given : Side of square is 10 m
Area of square = 102
Area of square = 10 × 10
Area of square = 100 m2
II. Area of rectangle = Length × Breadth
Given : Length is 11 m and Breadth is 10 m
Area of rectangle = 11 × 10
Area of rectangle = 110 m2
III. Area of triangle = 1/2 × Base × Height
Given : Base is 11 m and Height is 20 m
Area of triangle = 1/2 × 11 × 20
Area of triangle = 110 m2
Therefore From I, II and III we get;
Area of square = 100 m2
Area of rectangle = 110 m2
Area of triangle = 110 m2
Thus,
Area of Rectangle = Area of triangle > Area of square.
问题2:计算这些形状中哪个形状会包围更多的面积?
半径为 20 厘米的圆(使用 π = 3.14)
底边为 40 厘米,高为 30 厘米的平行四边形
平行边长 15 厘米和 20 厘米,高 40 厘米的梯形
解决方案:
I. Area of circle = πr2
Given : Radius is 20 cm
Area of circle = 3.14 × 20 × 20 (Using π = 3.14)
Area of circle = 1256 cm2
II. Area of parallelogram = Base × Height
Given : Base is 40 cm and Height is 30 cm
Area of parallelogram = 40 × 30
Area of parallelogram = 1200 cm2
III. Area of trapezium = 1/2 × (Sum of parallel sides) × Height
Given : Height is 40 cm and Parallel side are 15 cm and 20 cm
Area of trapezium = 1/2 × (15 + 20) × 40
Area of trapezium = 700 cm2
Therefore,
Area of circle (1256 cm2) > Area of parallelogram (1200 cm2) > Area of trapezium (700 cm2).
问题 3. 找出哪个图形的周长最大?
边长 50 m
长 65 m 宽 30 m 的矩形
边长为 65 m 的等边三角形
解决方案:
Here,
I. Perimeter of square = 4 × Side
Given : Side is 50 m
Perimeter of square = 4 × 50
Perimeter of square = 200 m
II. Perimeter of rectangle = 2 × (Length + Breadth)
Given : Length is 65 m and breadth is 30 m
Perimeter of rectangle = 2 × (65 + 30)
Perimeter of rectangle = 2 × 95
Perimeter of rectangle = 190 m
III. Perimeter of Equilateral triangle = Side + Side + Side
Given : Side is 65 m
Perimeter of Equilateral triangle = 65 + 65 + 65
Perimeter of Equilateral triangle = 195 m
Therefore,
Perimeter of square = 200 m > Perimeter of Equilateral triangle = 195 m > Perimeter of rectangle = 190 m.
问题 4. 找出有多少个边长为 2 m 的小正方形和由一个边长为 8 m 的大正方形组成?
解决方案:
As we know that,
Area of square = Side × Side
Area of large square = 8 × 8
Area of large square = 64 m2
Now,
Area of small square = Side × Side
Area of small square = 2 × 2
Area of small square = 4 m2
Further finding how many small squares can be formed from the large square
⇒ Area of large square/Area of small square
⇒ 64/4
⇒ 16 times
Therefore,
16 small square can be formed from a large square.