Ruler Plus

About this app

This accurate ruler allows you to measure many geometric properties specific to common 2D shapes, like length, perimeter, area, width, height, radius, angle, and circumference. Simply place a small object on your device's screen and, after a few intuitive taps, you'll find out the numerical values of its area and perimeter.

How it works

To move between pages, just tap the arrow buttons from the top ('<' or '>').
First two pages of this app let you measure the dimensions of an object (length, width, height) or the angles between its sides. The next eight pages
are designed for regular-shaped objects, such as squares, rectangles, circles, ellipses, triangles, circular rings and more. Tap on the bottom-right button to switch between displayed characteristics, for example between area and perimeter, or radius and circumference. Also, you can tap on the question mark to see which mathematical formulas were used for calculations.
There are two methods you can employ to perform accurate measurements, Cursor and Automatic modes.

Cursor mode: If one or two cursors are selected, you can manually adjust their positions and obtain a perfect alignment with the object's edges. Or, for a regular object, to have it perfectly fit inside the screen's red area.

Automatic mode: In case the object's edges prevent you from freely move the red cursors, you can activate the automatic mode by pressing the 'oo' button. The current cursor's) will flash a few times, and now you can select what will be its change in position - for example, 0.1, 0.5, 1, 5 or 10 millimeters if the metric system is selected. Move the cursor by tapping the '+' and '-' buttons until the object is perfectly aligned within the red zone, then read its area or perimeter.

For a regular 3D object, you can repeat these steps for each side-surface and then calculate a global parameter, such as its total area or volume.

Observation: to have more accurate results, look perpendicularly to the screen and set its brightness to a higher value.

- two units of measurement, cm and inches
- fraction or decimal inches for lengths
- selectable steps for the automatic mode
- two cursors with multi-touch capability
- show formulas used for each geometric shape
- no permissions required, no ads displayed
- speech options (set the speech engine to English)