# Right Angle — Triangles, trapezoids, circles

> Calculator for solving triangles and circle segments with multiple angle units. (iPhone/iPad app by Jerry Mayers.)

- Source: https://appshunter.io/ios/app/right-angle/id292390648 (this page in markdown: same URL + `.md`)
- Developer: [Jerry Mayers](https://appshunter.io/developer/287638654)
- Category: Productivity, Utilities
- Price: Free with in-app purchases
- Rating: 3.90/5 from 30 App Store ratings · 86 written reviews indexed
- Age rating: 4+
- Requires: iOS 26.0 · 2 MB
- Languages: American English
- Released: 2008-10-04
- Data updated: 2026-07-17
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/right-angle/id292390648/reviews.md

## What is Right Angle?

Right Angle is a calculator built for carpenters, builders, surveyors,
machinists, and engineers — anyone who needs to solve a triangle, a
trapezoid, or a circle without reaching for a notepad and the law of
sines.

Enter any valid combination of sides and angles and Right Angle solves
the rest, including perimeter and area. The right triangle calculator
is included for free; every other shape unlocks with a one-time Pro
purchase or subscription.

SHAPES
• Right triangle (free)
• Oblique triangle
• Isosceles, right, and general trapezoids
• Full circle — enter radius, diameter, or circumference
• Segment of a circle

ANGLE FORMATS
• Decimal degrees
• Radians
• Degrees / minutes / seconds (DMS)
• Percent grade
• Pitch (x-over-12)

LENGTH FORMATS
• Decimal — the original, unitless entry. Best for metric.
• Feet, inches & fractions — type values like 2' 5 1/2".
• Inches & fractions — type values like 40 1/2".
Pick a fraction precision from 1/2 down to 1/64 inch. Inputs and outputs
both use the format you choose, and you can switch any time from Settings.

DESIGNED FOR THE JOB SITE
• A custom on-screen keyboard puts the symbols you need — feet, inches,
  fraction slash, degree, prime, double-prime — one tap away.
• Helpful errors when an input combination can't be solved, instead of
  silent failures.
• Available in English and Spanish — iOS picks the language to match
  your device.
• Full VoiceOver support across the keyboard, input fields, shape
  diagrams, and results. Animations respect the Reduce Motion setting.

EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy policy: http://rightangleapp.com/privacy.html

## Key features

- Triangle solver
- Circle segment calculator
- Multiple angle units (degrees, radians, DMS, grade, x/12)
- Oblique triangle solver (add-on)
- Circle segment solver (add-on)
- Free right triangle calculator

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Renews Monthly | $2.99 | per month |
| Renews Yearly | $14.99 | per year |

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Segments Calculator | $5.99 | one-time |
| Oblique Triangle Calculator | $5.99 | one-time |
| Segment & Oblique Triangle | $6.99 | one-time |
| Small Tip | $2.99 | one-time |
| Medium Tip | $4.99 | one-time |
| Large Tip | $9.99 | one-time |
| Huge Tip | $29.99 | one-time |


## Recent user reviews (10 of 86)

All indexed reviews: https://appshunter.io/ios/app/right-angle/id292390648/reviews.md

### 1/5 — Recently Useless

*2025-01-24*

We needed an app that handled imperial measurements in fractions. This was it until now. i can interpret decimals to fractions in my head but this app does neither to provide answers. What was once useful & unique is now useless & DELETED! goodbye!

### 1/5 — Most recent update ruined this app

*2024-11-11*

This app was 5 stars for the years I’ve used it but when I opened it yesterday and seen the option for feet and inches on the calculator was removed I was disappointed and now I have to convert all my measurements to decimals and back to get accurate measurements, I might as well just use the formula on my pipe trades calculator.

### 1/5 — WHY

*2024-11-10*

WHY DID YOU REMOVE THE FRACTIONS….INSTEAD OF UPDATING IT YOU SET THE APP BACKWARDS

**Developer response:** Very few users were using fractions, and it greatly complicated number input and accuracy.

### 5/5 — Best Angle App

*2024-11-03, version 5.4.0*

Been using this App for well over 10 years now makes my job so much easier.

### 2/5 — Changed for the worse

*2024-04-30*

Used this app for a long time because it would figure both of the angles of a right triangle but the app was updated and now it only provides one.

**Developer response:** It does show both angles of a right triangle. There is an angle A & angle C field just below it.

### 2/5 — Lose Your purchase

*2024-04-24*

If you do this update, you will lose your previously purchased unlocked app. And you now need to spend $4.99 to unlock the features that you paid for previously I tried to restore my purchase and it did not work. Fortunately, I did not update the app on my other phone so I still have a version that will work. And I am using it right now for work and messing around with. It is not something I wanted to do right now. I’m just not about the money, I’d love to pay the extra five bucks to help keep this app going, but it’s the principle and the timing that stinks

**Developer response:** If you try updating to >= 5.4.0 this should be fixed.

### 5/5 — After 4 years

*2023-10-27, version 5.1.1*

Well after 4 years of using this app I STILL LOVE IT!!! I use it at work still all the time.

### 1/5 — Keeps telling me to pay

*2020-05-05*

I see why now that I saw the owner write a review on his own app

**Developer response:** I’m sorry about this. If you download version 4.4.3 that bug should be fixed. It would be worth you trying the “Restore Purchases” button in the app.

### 1/5 — Does not work

*2019-11-01, version 4.3.1*

This app does not work unless you send a tip or purchase it, totally misleading when it says it’s free

### 5/5 — Love it

*2019-05-17, version 4.3.1*

Use this for work making fencing and railings.
Absolutely brilliant.

## Frequently asked questions about Right Angle

### What does the Right Angle app do?

Right Angle is a specialized calculator designed to solve problems related to triangles and segments of circles. It allows users to input angles in various formats and provides solutions for different types of triangles and circle segments.

### What are the key features of Right Angle?

Key features include a triangle calculator, a circle segment calculator, and support for multiple angle units like degrees, radians, degrees minutes seconds, % grade, and x over 12. The right triangle calculator is included for free, with optional add-ons for oblique triangles and more complex circle segments.

### Is Right Angle free to use?

The core functionality, including the right triangle calculator and basic angle calculations, is free. However, advanced features like solving oblique triangles and segments of circles require optional add-ons, which are available through in-app purchases.

### What types of angles can be entered?

The app supports a wide range of angle input formats. You can enter angles in degrees, radians, degrees minutes seconds, % grade, and x over 12. This flexibility caters to various mathematical and engineering needs.

### Who would benefit from using this app?

This app is beneficial for students learning geometry and trigonometry, engineers working on design and construction projects, and anyone who frequently needs to perform precise calculations involving triangles and circles.

## Version history (last 5 releases)

### 6.0.1 — 2026-07-10

Bug fixes

### 6.0.0 — 2026-05-21

• Now available in Spanish — iOS picks the language to match your device.
• Three new trapezoid solvers: isosceles, right, and general. Enter the sides and angles you know and the rest fills in, along with area and perimeter.
• A new full-circle solver — type any one of radius, diameter, or circumference and the other two plus the area come back.
• On smaller screens, the input you're editing now scrolls up above the keyboard so the instructions and any error stay visible.
• The keyboard fades in smoothly when Reduce Motion is enabled.

### 5.8.0 — 2026-05-17

What's New

• Feet, Inches & Fractions: A new Settings option lets you enter
  and display lengths as feet/inches with fractions (e.g. 2' 5 1/2")
  or inches with fractions (e.g. 40 1/2"). Decimal stays the default,
  so metric users won't be affected. Pick a fraction precision from
  1/2 down to 1/64 inch.

• More Oblique Triangle solutions: Seven additional input combinations
  the Oblique Triangle calculator couldn't previously solve are now
  supported, including new "two sides + one angle" and "one side + two
  angles" arrangements.

• Bug fixes:
  – Right triangles entered as two sides plus the opposite angle no
    longer return a negative third side in certain cases.
  – Entering 0° 0' 0" no longer crashes the app — you'll see a clear
    error instead.
  – Oblique triangles with two angles totaling 180° or more now show
    a helpful error rather than a nonsensical result.
  – The percent-grade key on the keyboard now shows the correct symbol.

### 5.7.3 — 2026-04-06

Fix crash

### 5.7.2 — 2026-04-05

Bug fixes

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-17.*