An isosceles triangle is a triangle with two equal sides and two equal angles. If you need to find the perimeter, area, or other properties of an isosceles triangle, you can use an Isosceles Triangles Calculator. This tutorial will show you how to use an Isosceles Triangles Calculator and explain the formula used to find the perimeter, area, and other properties of an isosceles triangle.
| Given lengths of sides a and b; Find c, P, s, K, ha, hb and hc | |
| side a = | |
| side b = | |
| Length Units* | |
| a and b are known; find c, P, s, K, ha, hb, and h |
| side a = 8 m |
| side b = 5 m |
| side c = 8 m |
| perimeter = 21 m |
| Semiperimeter = 10.5 m |
| area = 18.9984 m2 |
| altitude of a = 4.74959 m |
| altitude of b = 7.59934 m |
| altitude of c = 4.74959 m |
The first step in using an Isosceles Triangles Calculator is to input the measurements of the triangle. You'll need to input the length of the two equal sides and the angle between them into the calculator. For example, if the two equal sides are 5 cm each and the angle between them is 60 degrees, then you would input those values into the calculator.
The next step is to calculate the perimeter of the isosceles triangle. The perimeter is the sum of the lengths of all three sides of the triangle. For an isosceles triangle, the length of the third side can be calculated using the following formula:
where s is the length of the two equal sides and b is the length of the base (the third side).
Using our example values, the perimeter of the isosceles triangle can be calculated as follows:
Since the two equal sides are each 5 cm, we know that the base is also 5 cm. Therefore:
The next step is to calculate the area of the isosceles triangle. The formula for the area of a triangle is:
where b is the base of the triangle and h is the height.
Since the isosceles triangle has two equal sides, the height can be calculated using the following formula:
where s is the length of the two equal sides and b is the length of the base.
Using our example values, the height of the isosceles triangle can be calculated as follows:
Height = (5√(4(52) - 52))/10
Height = (5√(75))/10
Height = 1.9365 cm
Now that we have the base and the height of the isosceles triangle, we can calculate its area:
Area = (1/2)(5)(1.9365)
Area ≈ 4.8413 square centimeters
Depending on the Isosceles Triangles Calculator you're using, you may be able to calculate other properties of the triangle, such as the angles or the length of the altitude. Be sure to explore all the features of the calculator to see what other information it can provide.
An Isosceles Triangles Calculator can save you time and effort in finding the perimeter, area, and other properties of an isosceles triangle. By following the steps outlined in this tutorial and using the formulas for perimeter, area, and height, you can easily calculate these measurements for any isosceles triangle.
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