# Mathematical Playground - 3D Shapes -

This is an educational tool that is useful for learning or teaching about three dimensional shapes in mathematics. It is recommended to not only students, but also teachers.

By enabling to draw three dimensional shapes and measuring dimensions or angles, you can get hints to understand shapes well.

## View from Free Angles

You can touch screen to change the camera angles as you like.

## Print and Share Screen

You can adjust print size. Also, you can share it with devices including your mac-pc, etc....

## Cut Shapes

You can specify three points on a shape and cut it by the face that includes the three points.
You can also translate the cutting plane.

## Expand a shape

Using the Expansion-option in the Face-tool, you can expand a shape by face-by-face.
Faces rotete around one of their edges, so that the resulting net form (development diagram) varies depending on which face you select.

## Measuring

You can measure angles, distances, area or volume on a shape. You can get the volume of any shape!

## Edge / Shape Extension

Some shape's volume measure can be calculated by extending.
A shape can be extended if and only if there are enough extended edges.

## Draw Lines to Faces

Now you can draw lines on faces.
To draw lines, use the Cut-Point tool.
When there are just two cut-points and they are on the same face, the Draw Line option is available, which draws a line on the face.

This is a compact calculator on the corner of the screen.
It appears as an icon in the beginning. You can capture numbers from labels such as lengths, distances, angles, etc...

And you can refer guidance by tapping the icon while the guide is in the screen.

The following is a demonstration movie that calculates the volume of regular icosahedron using formula.

## Data Distribution

This app enables you to distribute the shape data using Wi-Fi or Bluetooth connectivity.
With this functionality, you can distribute the data locally without any server.

## Exporting Screen Shot

You can export screen shots as well as share them.
Note that the two kinds of screen shots are available : print-ready and camera-ready. The print-ready one is good for print. However, note that shape data cannot be shared using e-mail or SNSs.

## Saving the Shape Data

You can save a shape object including the net form (development diagram) into your device. Note that the data is stored in the app bundle, which means the data will be disposed on removing this app.

## Hand-Writing Memo tool

This app is powered by an overlay drawing tool. It could be the great help not only in studing but also in teaching. Espeially, when you output the video to TV using the HDMI connector or Air-Play correspondance display in the class, this functionality would support you strongly.

Now you can use this app under the split-view mode of the multi-tasking. So that you can import the picture in another app that is exported from this app.

## Scene

Scene is like a snap-shot of 3D shapes. You can access to several scenes quickly.
To access or manage scenes, use Scene Manager, which is available from both the Scene Selecting screen and the Workspace screen.

## Variety of shapes

There are 13 shapes are available by default.
But note that this app cannot treat shapes that have circle such as a cylinder, a sphere, etc...

## Lite Version

There is free version of this app in which some functionalities are unavailable. Please try it. And if you like this app, please purchase the full-version!!! Thank you. ;-)

## Notice

The version 2.0.9 of this app has been released on Mar.1.2021.
But it still has a bugs in sharing shape data.
We will release the fixed version (2.0.10) in a few days.
Once it has been released, please keep your app up to date.

This release includes following improvements:
•Distributing / receiving the shape data are now available on iOS 14.
•Fixed the bug that the app was crushed that once you expand the corn / pole and then fold completely.
•Fixed the following bug: when you loaded a shape with being already expanded, you ware able to fold it using expansion history slider, but no longer ware able to expand it again.
•Improved the layout of the Scene Manager, which makes it more easy to use.

There lives a built-in guide man in this app, and he will give a basic explanation. We provide additional intormation here.

### Q. I can neither save nor start server in the Menu screen.

A. This is because no shape is currently selected. Please push done in the Menu screen, and select a shape using Shape Tool, then try again.

1. Privacy data collected by this application
This application collects no user's privacy data by itself such as contact address, IP address, SNS account name, etc. However, if you tell us your mail address for the reply on the contact form on our homepage, the e-mail address will be included in the inquiry contents, which will be received in our e-mail box.
2. Sharing privacy data
Basically, we do not share mail address with third parties. However, depends on the content of the e-mail, we may provide information to a appropritate agency without prior consent.
3. Saving and deleting privacy data
The mail address information will be promptly deleted from the receiving mail box and the sending mail box after a series of interactions are completed.

## Compatibility

This app runs on the following devices and operating systems.

### Device:

iPhone® series

iPod® series
iPod touch® (5th generation or newer).

### Other Requirements:

WiFi or Bluetooth communication feature is required in order to use " On the air distribution " feature.

30 Jun. 2017.

## Media

This app was reviewed to be awarded 5 stars of the EAS Certification!