# DIY a Tablet Stand to Meet My Favorite View Angle

It’s easy to make a tablet stand with corrugated fiberboard (aka corrugated paper). To customize view angle, I use Google Calculator and trigonometric functions to do the math.

# Design Draft

First, I disassemble a corrugated paper box and draw a design draft: A design draft of a tablet stand with a stopper

# Trigonometric Functions

Here is what I have already known:

1. Max length (A+B+C+D) of corrugated paper.
2. A is equal to tablet height.

At first, I just let b (length of B) = c (length of C) = d (length of D) = (total length – tablet height) / 3. Then I get a stand with 60° view angle according to an equilateral triangle.

How to customize θ? I decide to let b = c to make it a Isosceles triangle.

Based on Pythagorean theorem, I get d = 2b * cosθ or use the formula below: Pythagorean theorem of the lengths among an isosceles triangle.

You need a scientific calculator which supports trigonometric functions here. Because my Sony Xperia C3‘s build-in calculator doesn’t support Inverse trigonometric functions, I decide to install Google Calculator after reading 10 best calculator apps for Android on Android Authority.

Launch and swipe left, you see more functions and operators. There is a DEG (degree) or RAD (radian) on the upper left. Click to select the unit you need.

If you want to calculate θ with a given d, you need to use inverse trigonometric functions. In some calculators, there is a Inv (inverse) button to help you switch from sine to arcsine (or sin¯¹(x)) and vice versa. But in Google Calculator, you need to tap and hold for about 0.5 second. It enters the inverse trigonometric function automatically as below: