Trigonometry Help Lite is an iPhone application developed by Armchair Engineering. It is a simple triangle calculator that allows users to quickly and easily find unknown angles and sides of any right-angled triangle. This free app is a handy tool for students and professionals alike.

The main features of Trigonometry Help Lite include accurately solving right-angled triangles, providing a workings view to see the math behind the solutions (requires optional upgrade), displaying a scale drawing of the solved triangle, and offering a set of basic trigonometry formulas. Users can enter angles in radians, decimal degrees, or degrees, minutes, seconds, and can also select their preferred number of decimal places.

According to two App Store reviewers, Trigonometry Help Lite has received positive feedback. One reviewer mentioned how they could never remember the simple formulas and had to constantly refer back to their textbooks. They found this app to be a delightful tool that they loved using, even impressing their engineer friends. The other reviewer praised the app for being easy to use, accurate, and precise, recommending it to any toolmaker.

Trigonometry Help Lite is also available for macOS on the Mac App Store.