Enter side lengths and click either Top Angle input or Base Length input to select (turns green) and enter its known value.
Hit Calculate to calculate, re-draw and display all other angles, side lengths and triangle height, from selected entries.
Mouse over arrows
to auto increment / decrement the Top Angle and re-draw the Isosceles Triangle repeatedly to animate.
Use this Isosceles Triangle Calculator to lay-out or measure angles and side lengths by entering 2 known values (Side Lengths and either Top Angle or Base Length) to find all other side lengths, angles and triangle height.
E.g: on a construction site, to measure an existing angle, measure down both sides form the top angle, then measure across (the base) to find entries needed to calculate the angle.
To lay-out a known angle, enter the angle and side lengths to calculate the base length needed to mark out the correct angle.