1. Side (base) of an isosceles trapezoid if you know other base and midline of a trapezoid
, 
- bases
- midline
Calculate the base of an isosceles trapezoid if given middle line and other base ( a b ) :
2. All four sides of an isosceles trapezoid if you know height, angle at the base and other sides
- smaller base
- larger base
- leg
- angle at the base
- height
Calculate the lateral side (leg) of a trapezoid if given angle at the base, height or bases ( c ) :
Calculate the base of a trapezoid if given angle at the base, height and other base ( a b ) :
Calculate the base of a trapezoid if given angle at the base, lateral side (leg) and other base ( a b ) :
3. Bases of an isosceles trapezoid if you know height, diagonals and angle between the diagonals
- smaller base
- larger base
- leg
- diagonal
, 
- angles between the diagonals
- height
Calculate the side (base) of a trapezoid if given diagonal, lateral side (leg) and other base ( a b ) :
Calculate the lateral side (leg) of a trapezoid if given diagonal and bases ( c ) :
Calculate the side (base) of a trapezoid if given diagonal, height, angle between the diagonals and base ( a b ) :
* It is true in this case:
4. Sides of an isosceles trapezoid if you know area of a trapezoid
, - bases
- leg
- midline
, - angles at the base
- height
- area
Calculate the side (base) of a trapezoid if given area of a trapezoid ( a b ) :
Calculate the lateral side (leg) of a trapezoid if given area of a trapezoid ( c ) :
* It is true in this case: