# Fly in a Square and Triangle

## Overview

• Program a Parrot drone to fly along a square and a triangular route, by turning to specific heading angles and flying.

## Objectives

• Understand heading angles (0 to 360 degrees).

• Combine turning blocks and motion blocks to turn the drone to the proper headings for flying in a square and triangle pattern.

• Use repeat loops to fly in the same pattern using fewer code blocks.

• Learn about the geometry concept "exterior angles".

## Steps

### Create a Drone Project

• Create a new drone project by tapping `+ New Project` via "MY PROJECTS". Choose the template that matches the model of your Parrot drone. Here we use the Parrot Airborne Night as an example.

### Turning a Complete Circle

• Heading angle is the angle that the drone is facing or pointing.

• The figure below shows heading angles at 90-degree increments. To turn a full circle, a drone has to turn its heading angle for a total of 360 degrees.

### Fly in a Square Route

• Use the block in `Motion` category, `turn right by 90 degrees`, to turn the heading angle of the drone by a specified angle.

• The following blocks move the drone in a square:

### Understanding the Components of a Square

• Notice that the drone has made a complete square by turning 4 times, turning a total of 360 degrees to return to its original heading. The degrees to turn each time is 360 degrees divided by 4, which is 90 degrees.

### Fly in a Square Route using `repeat` Loops

• A `repeat *n* times` loop is used when the number of iterations can be calculated and known in advance. In our case for flying along a square route, the same blocks (`move forward for 2 secs` and `turn right by 90 degrees`) will be performed 4 identical times. Therefore, we can use the block `repeat 4 times` to replace the redundant blocks, and the program would look like this:

### Program the Drone to Fly in a Triangle

• To fly in a triangle, the drone has to turn 3 times to complete a full 360° turn. The number of degrees to turn each time is then 360° divided by 3 = 120° .

• The program should look like this:

### Challenges: Fly in a Pentagon (5 sides) and a Hexagon (6 sides)

• Calculate the degrees to turn each time by dividing 360° by the number of the sides of the geometric shape. The following in an example program for the Pentagon:

• In geometry, an angle of a polygon is formed by two sides of the polygon that share an endpoint. An exterior angle (or external angle) is an angle formed by one side of a simple polygon and a line extended from an adjacent side. This is the turning angles that you’ve been calculating throughout this lesson.

• The sum of all exterior angles of a polygon is 360°, and each exterior angle of a regular polygon is 360° divided by the number of sides.