1. To find the missing base length of a trapezoid (called a trapezium in the UK) if you know other base and midsegment  

sides trapezoid m

 

a , b     -  bases of a trapezoid

m red  - middle line

 

 

Formulas for trapezoid base. Click on the formula image to use the calculator.

sides trapezoid m F asides trapezoid m F b

 

 

2.  To find the legs and bases of a trapezoid (trapezium UK) with height, angle and other sides  

sides trapezoid h

 

a , b     -  bases

c black , d black     -  legs of a trapezoid

alpha red , beta2 blue     -  angles  at the base

h  - height

 

Formulas for trapezoid base if given height, base angle and other base

sides trapezoid h F1

sides trapezoid h F2

 

Formulas for trapezoid base if given leg, base angle and other base

sides trapezoid F12

sides trapezoid F13

sides trapezoid F14

sides trapezoid F15

 

Formulas for trapezoid legs if given base angles and other leg

sides trapezoid F10sides trapezoid F11

 

 

Formulas for trapezoid legs if given base angles and height

sides trapezoid h F5sides trapezoid h F6

 

 

3.  To find bases of a trapezoid (trapezium UK) with height, diagonals and angle between them  

sides trapezoid d

 

a , b     -  bases

d1 blue , d2 blue     -  diagonals

alpha red , beta brown     -  angles between the diagonals

h  - height

 

Formulas for calculating trapezoid base if given height, diagonals and angle between them

sides trapezoid d F1

sides trapezoid d F2

* It is true in this case:

sides trapezoid d F