Answer:
Geometric proof in explanation.
Step-by-step explanation:
Draw an equilateral triangle.
A equilateral triangle has it's sides all congruent and all it's angles measures 60 degrees.
We are going to draw a line segment to cut the equilateral triangles into two congruent right triangles. I will do this in the attachment with p being positive.
You can see we will get 30-60-90 triangles.
We don't need to find the adjacent measurement to the angle whose measurement is 30 degrees since sine is opposite over hypotenuse.
![\sin(30^\circ)=\frac{\frac{p}{2}}{p}=\frac{p}{2} \cdot \frac{1}{p}=\frac{1}{2}](https://tex.z-dn.net/?f=%5Csin%2830%5E%5Ccirc%29%3D%5Cfrac%7B%5Cfrac%7Bp%7D%7B2%7D%7D%7Bp%7D%3D%5Cfrac%7Bp%7D%7B2%7D%20%5Ccdot%20%5Cfrac%7B1%7D%7Bp%7D%3D%5Cfrac%7B1%7D%7B2%7D)
![\sin(30^\circ)=\frac{1}{2}](https://tex.z-dn.net/?f=%5Csin%2830%5E%5Ccirc%29%3D%5Cfrac%7B1%7D%7B2%7D)