Trapezoid

Trapezoid

Perimeter

P = a + b + c + d

Area

A = m · h

Midsegment

m = a + c 2

Spetial Trapezoids - Isosceles Trapezoids

- Tangent Quadrilateral

Isosceles Trapezoid

a+b=2c

Attention! Not all isosceles trapezoids are tangent quadrilaterals!

Area with the radius of the inscribed circle

s=a+b+2c4

A=s·r

Spetial Trapezoids - Isosceles Trapezoids - Cyclic 

Quadrilateral

 

Isosceles Trapezoid

d2=a·b+c2

Attention! All isosceles trapezoids are also cyclic quadrilaterals!

Area with the radius of the circumscribed circle

A=d·c·a+c4R

Keywords: trapezoid, perimeter, area