# Rounded Corner Rectangle

Written by Jerry Ratzlaff on . Posted in Plane Geometry

• Rounded corner rectangle (a two-dimensional figure) is a quadrilateral with two pair of parallel edges and rounded corners.
• Diagonal is a line from one vertices to another that is non adjacent.

### Area of a Rounded Corner Rectangle formula

$$\large{ A_{area} = a \; b - r^2 \; \left( 4 - \pi \right) }$$

Where:

$$\large{ A_{area} }$$ = area

$$\large{ r }$$ = corner radius

$$\large{ a, b, c, d }$$ = edge

$$\large{ \pi }$$ = Pi

### Diagonal of a Rounded Corner Rectangle formula

$$\large{ D' = \sqrt{ \left( a - 2\;r \right)^2 + \left( b - 2\;r \right)^2 } + 2\;r }$$

Where:

$$\large{ D' }$$ = diagonal

$$\large{ r }$$ = corner radius

$$\large{ a, b, c, d }$$ = edge

### Perimeter of a Rounded Corner Rectangle formula

$$\large{ p = 2 \; \left[ a + b - r^2 \; \left( 4 - \pi \right) \right] }$$

Where:

$$\large{ p }$$ = perimeter

$$\large{ r }$$ = corner radius

$$\large{ a, b, c, d }$$ = edge

$$\large{ \pi }$$ = Pi