## Enter 2 values below

<-- Length
<-- Width
<-- Area
<-- Perimeter

A rectangle has width of 4 and perimeter of 28

Calculate the length and area

P = 2(l x w)

P = 2l + 2w

P - 2w = 2l

##### Divide each side by 2

 P - 2w 2
 =
 2l 2

 l  = P - 2w 2

 l  = 28 - 2(4) 2

 l  = 28 - 8 2

 l  = 20 2

l = 10

##### Calculate Area (A):

A = l x w
where l = length and w = width

Plug in l = 10 and w = 4

A = 10 x 4

A = 40

##### Calculate diagonal length

Diagonal = √l2 + w2
where l = length and w = width

Plug in l = 10 and w = 4

Diagonal = √102 + 42

Diagonal = √100 + 16

Diagonal = √116

Diagonal = 10.770329614269

##### Calculate the circumradius R:

 R  = √l2 + w2 2

 R  = √102 + 42 2

 R  = √100 + 16 2

 R  = √116 2

 R  = 10.7703 2

R = 5.3851648071345

 r  = 40 14

##### Calculate the inradius r:

 r  = lw l + w

 r  = (10)(4) 10 + 4

 r  = 40 14

r = 2.8571428571429

##### Other Properties:

Faces = 1

Edges = 4

Vertices = 4

w = 4
P = 28
A = 40
Diagonal = 10.770329614269
R = 5.3851648071345
r = 2.8571428571429
Faces = 1
Edges = 4
Vertices = 4

##### What is the Answer?
w = 4
P = 28
A = 40
Diagonal = 10.770329614269
R = 5.3851648071345
r = 2.8571428571429
Faces = 1
Edges = 4
Vertices = 4
##### How does the Rectangles and Parallelograms Calculator work?
Free Rectangles and Parallelograms Calculator - Solve for Area, Perimeter, length, and width of a rectangle or parallelogram and also calculates the diagonal length as well as the circumradius and inradius.
This calculator has 4 inputs.

### What 2 formulas are used for the Rectangles and Parallelograms Calculator?

P=2l+2w
A=l*w

For more math formulas, check out our Formula Dossier

### What 9 concepts are covered in the Rectangles and Parallelograms Calculator?

area
Number of square units covering the shape
a radius of the circle inside which the polygon can be inscribed
a radius of an inscribed circle or sphere
length
the measurement or extent of something from end to end
parallelogram
simple quadrilateral with two pairs of parallel sides.
perimeter
The distance around a shape or object
rectangle
a quadrilateral with four right angles
rectangles and parallelograms
width
the measurement or extent of something from side to side.