如何求等边三角形的周长?
等边三角形是三个边相等且角也相等的三角形。等边三角形的每个角的值为60度,因此也称为等角三角形。等边三角形被认为是正多边形或正三角形,因为角度相等且边也相等。
例如,在三角形中,ABC 相等,即
AB = BC = CA = 一个单位。
此外,∠A、∠B 和 ∠C = 60°
等边三角形的性质
- 三边相等。
- 所有三个角度都等于 60°
等边三角形的周长
等边三角形的半周长
等边三角形的半周长 =
让我们假设 a 是等边三角形的边。
换句话说,我们有,
等边三角形的半周长 =
给定面积时等边三角形的周长
让我们假设 a 是等边三角形的边。
等边三角形的周长可以使用其面积来计算,由下式给出,
现在,
我们知道,
等边三角形的周长 = 边 + 边 + 边
等边三角形的周长,P 由 = 3 × a
因此,值 a 可以用 P/3 代替。
给定高度时等边三角形的周长
当给定三角形的高(高)时,可以计算出等边的周长。
我们有,
等边三角形的高度 =
在代入等边三角形周长的值后,我们有,
等边三角形的周长 = 边 + 边 + 边
等边三角形的周长 = 3 × a
所以,
高度(或高度)=
示例问题
问题 1. 等边三角形的边长为 30√3 厘米,计算其周长。
解决方案:
Here we have to find the perimeter of an equilateral triangle
We are given that the side of the equilateral triangle is 30√3 cm
As we know that
Formula for perimeter of an equilateral triangle
Perimeter of an equilateral triangle = Side + Side + Side
Perimeter of an equilateral triangle = 3 × a
where a is side of an equilateral triangle
Perimeter of an equilateral triangle = 3 × 30√3
Perimeter of an equilateral triangle = 90√3 cm
Therefore,
Perimeter of an equilateral triangle is 90√3 cm.
问题 2. 如果等边三角形的边是 90 m,那么求三角形的周长和半周长?
解决方案:
Here we have to find the perimeter and semi-perimeter of an equilateral triangle,
First finding the perimeter of an equilateral triangle
We are given that the side of the equilateral triangle is 90 m
Formula for the perimeter of an equilateral triangle
Perimeter of an equilateral triangle = Side + Side + Side
The perimeter of an equilateral triangle = 3 × a
Substituting the value of a in the formula
Perimeter of an equilateral triangle = 3 × 90
Perimeter of an equilateral triangle = 270 m
Further finding the semi-perimeter
Formula for semi-perimeter of an equilateral triangle =
Where a is the side of an equilateral triangle
Substituting value of a in the formula
Semi-perimeter of an equilateral triangle =
Semi-perimeter of an equilateral triangle = 135 m
Therefore,
Perimeter of an equilateral triangle is 270 m and semi-perimeter of an equilateral triangle is 135 m.
问题 3. 假设一个等边三角形的面积是 100√3 cm 2 ,那么计算它的周长?
解决方案:
Here we have to find the perimeter of equilateral triangle using its area
Formula for equilateral triangle area =
Area of equilateral triangle = 100√3
100√3=
a2 =
a = √400
a = 20
Therefore,
Side of the equilateral triangle is 20 cm
Now further finding perimeter of equilateral triangle
Perimeter of equilateral triangle = side + side + side = 3a
Perimeter of equilateral triangle = 3 × 20
Perimeter of equilateral triangle = 60 cm
问题 4. 如果三角形的高为 35√3 m,求等边三角形的周长。
解决方案:
Here we have to find the Perimeter of the equilateral triangle with the height 35√3 m
Formula for calculating perimeter using height is given below
Height =
Here a is the side of the equilateral triangle
35√3 =
a =
a = 70 m
Now further finding perimeter of the equilateral triangle
Perimeter of equilateral triangle = side + side + side = 3a
Perimeter of equilateral triangle = 3 × 70
Perimeter of equilateral triangle = 210 m
问题5.如果等边三角形的边是23厘米,那么求等边三角形的周长和高?
解决方案:
Here we have to find the perimeter of an equilateral triangle
We are given that the side of the equilateral triangle is 23 cm
As we know that
Formula for the perimeter of an equilateral triangle
Perimeter of an equilateral triangle = Side + Side + Side
Perimeter of an equilateral triangle = 3 × a
where a is side of an equilateral triangle
Perimeter of an equilateral triangle = 3 × 23
Perimeter of an equilateral triangle = 69 cm
Further finding the height of the triangle
Height =
Here a is the side of the equilateral triangle
Substituting the value of a in the formula
Height =
Height = 11.5√3
Therefore,
Perimeter of an equilateral triangle is 69 cm and the height of an equilateral triangle is 11.5√3 cm.