﻿ 1.3.2 Exterior angle Project Shum Science for Kids

# Exterior angle

Exterior angles can be calculated with the knowledge that angles on a line add up to 180 degrees. Since we know that angles in a triangle add up to 180 degrees, we can calculate x as: $40\textdegree+56\textdegree+x=180\textdegree$ $\therefore x=180\textdegree-56\textdegree-40\textdegree$ $\therefore x=84\textdegree$  $84\textdegree+x=180\textdegree$ $\therefore x=180\textdegree-84\textdegree$ $\therefore x=96\textdegree$

More complex examples  $90\textdegree+x=120\textdegree$ (exterior angle of a triangle) $\therefore x=120\textdegree-90\textdegree$ $\therefore x=30\textdegree$

Another example:  $90\textdegree+38\textdegree+x=180\textdegree$ (angles of a triangle) $\therefore x=180\textdegree-90\textdegree-38\textdegree$ $\therefore x=90\textdegree-38\textdegree$ $\therefore x=52\textdegree$

Another example:  $144\textdegree=x+2x$ $\therefore 144\textdegree=3x$ $\therefore x=48\textdegree$

Another example:  $x=x/2+47\textdegree$ $\therefore x*x=2+47\textdegree$ $\therefore x^2=\sqrt(49\textdegree)$ $\therefore x=7\textdegree$