`1.  Diagonals of a trapezoid if you know sides and angles at the base  `

,      -  bases

,      -  legs

,      -  angles  at the base

,      -  diagonals

Find the diagonal of a trapezoid using the law of cosines  (  ) :

Find the diagonal of a trapezoid if given all four sides  (  ) :

`2.  Diagonals of a trapezoid using height  `

,      -  bases

,      -  legs

,      -  angles  at the base

,      -  diagonals

- height

Find the diagonal of a trapezoid using height, angles at the base and sides  (  ) :

`3.  Diagonals of a trapezoid if you know other diagonal, angle between the diagonals and height or area or midsegment  `

,      -  bases

,      -  diagonals

,      -  angles between the diagonals

- height

- midsegment

- areaof a trapezoid

Find the diagonal of a trapezoid if given other diagonal, angle between the diagonals and height or area or midsegment  (  ) :

* It is true in this case:

`4.  Diagonals of a trapezoid using formula for the sum of the squared diagonals   `

- lower base

- upper base

,      -  legs

,      -  diagonals

Formula for the sum of the squared diagonals   :

Find the diagonal of a trapezoid using formula for the sum of the squared diagonals  (  ) :