## Introduction

An isosceles triangle is a triangle that has two sides of equal length.

An acute triangle is a triangle in which all three interior angles are less than 90°.

An obtuse triangle is a triangle in which one of the interior angles is more
than 90°.

An equilateral triangle is a triangle in which all three sides have the same length.

All three angles of an equilateral triangle are 60°.

A right triangle is a triangle in which one angle is 90°.

A 90° angle is called a "right angle".

The relation between the sides and angles of a right triangle is the basis for trigonometry.

The sum of the interior angles of a triangle equals 180°.

## Isosceles Triangle

## Project #1

Create an isosceles triangle calculator with a menu interface.
For example ...

- The user selects what isosceles triangle data they will enter
*Note: Angles are assumed to be interior angles.*
- two angles and the side between them
*(angle side angle)*
- two sides and the angle between them
*(side angle side)*
- three sides
*(side side side)*

- ask the user to enter the data
- verify the data
- Negative and zero values are not allowed
*(angle side angle)* the sum of two angles must be less than 180°
*(side angle side)* the angle must be less than 180°
*(side side side)* the sum of the two smaller sides must be greater than the longest side
*(side side side)* two of the sides must be equal

- calculate the parts of the isosceles triangle (a, b, α, β)
- display the triangle's parts
- loop

See
math hints

- try breaking the isosceles triangle into smaller right triangles
- for some situations the law of cosines may work
- for other situations the law of sines may work

## Project #2

Create a GUI for the calculator.
See PySimpleGUI
.

## Project #3

Create a right triangle calculator?

Create a acute triangle calculator?

Create a obtuse triangle calculator?

Create a calculator for all triangles?

## Links

Triangle
(Wikipedia)

Right triangle
(wikipedia)

Euclidean geometry
(Wikipedia)

Non-Euclidean geometry
(Wikipedia)