,  ,     -  sides of a triangle

- semiperimeter

- circumcenter

Calculate the radius of a inscribed circle of a triangle if given all three sides ( r  ) :

- equal sides of a triangle

- circumcenter

Calculate the radius of a inscribed circle of an equilateral triangle if given side ( r  ) :

1.  Find radius of a circle inscribed if you know side and angle at the base

- equal sides of a triangle

- side  (base)

- angle  at the base

- circumcenter

Calculate the radius of a circle inscribed in an isosceles triangle if given sides ( r  ) :

Calculate the radius of a circle inscribed in an isosceles triangle if given side and angle ( r  ) :

2.  Find radius of a circle inscribed if you know side and height

- equal sides of a triangle

- side  (base)

- height

- circumcenter

Calculate the radius of a circle inscribed in an isosceles triangle if given side and height ( r  ) :

,    -  legs of a right triangle

- hypotenuse

- circumcenter

Calculate the radius of a inscribed circle of a right triangle if given legs and hypotenuse ( r  ) :

-  side of a square

- circumcenter

Calculate the radius of a inscribed circle of a square if given side ( r  ) :

`1.  The radius of a circle inscribed in a rhombus if you know diagonal, side and angle.  `

,    -  diagonals of a rhombus

- side

- acute angle of a rhombus

- circumcenter

Calculate the radius of a inscribed circle of a rhombus if given diagonals ( r  ) :

given side and angle ( r  ) :

given diagonal and angle ( r  ) :

given diagonal and side ( r  ) :

`2.  The radius of a circle inscribed in a rhombus if you know height  `

-  height of a rhombus

- side  of a rhombus

- circumcenter

Formula for calculating radius of a inscribed circle of a rhombus if given height ( r  ) :

-  upper base

-  lower base

-  height of a trapezoid

- circumcenter

Calculate the radius of a inscribed circle in an isosceles trapezoid if given height or bases ( r  ) :

-  side  of a polygon

-  number  of sides

- circumcenter

Calculate the radius of a inscribed circle of a regular polygon if given side and number of sides ( r  ) :

- equal sides of a hexagon

- circumcenter

Formula for calculating radius of a inscribed circle of a regular hexagon if given side ( r  ) :