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直角三角形求解器

测量计算器

Right Triangle Area from Inradius & Semiperimeter

Enter the inradius r and semiperimeter s to calculate the right triangle area.

通过半周长求面积 计算器

该计算器遵循 Area = r × s 并得出 Area。

输入数值以计算 Area。

What This Calculator Solves

Calculate the total area of a right triangle when the inradius and semiperimeter are known.

This tool uses the elegant relationship between a triangle's inscribed circle and its semiperimeter to find the area instantly.

Known values

Inradius r and Semiperimeter s

Finds

Area (A)

Main formula

A = r × s

Best for

Advanced geometry and circle theorems

Area Formula

A=r×sA = r \times s

For any triangle, the area can be found by multiplying the inradius (r) by the semiperimeter (s).

This formula (A = r × s) is universally true for all triangles, not just right triangles.

Diagram: Inradius and Semiperimeter

The diagram illustrates the inscribed circle with radius r. The area of the full triangle is exactly r multiplied by the semiperimeter s.

Diagram: Inradius and Semiperimeter Area formula A = r × s. a b c

Diagram Key

r = inradius

Radius of inscribed circle.

s = semiperimeter

Half the boundary distance.

A = area

Total enclosed space.

A = Area

Computed as r × s.

  • Both r and s must be positive lengths.

How to Calculate

  1. Identify inradius r and semiperimeter s.
  2. Enter r into the first field.
  3. Enter s into the second field.
  4. Multiply them to get the Area.

Worked Example

If inradius is 2 and semiperimeter is 12 (as in a 6-8-10 triangle):

A=r×sA = r \times s
A=2×12A = 2 \times 12
A=24A = 24

The area is 24 square units.

Where does this come from?

By splitting the triangle into three smaller triangles, each with height r and bases a, b, and c, their total area is 0.5*a*r + 0.5*b*r + 0.5*c*r = r*(a+b+c)/2 = r*s.

help

常见问题

关于直角三角形测量和面积的常见问题解答。

01 Does this work for non-right triangles? expand_more

Yes, A = rs works for any triangle.

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