Arrowhead |
Point |
Compass |
Straight Edge |
Alphabet |
Script View |
Choose point D on the shorter of AC or BC. | Common Notion 5 along with the implicit assumption that points exist on lines via Definitions 2, 3 and 4. |
Construct new point E on AB so that CE is equal to CD. | Proposition 3, Definitions 17 and 4. |
Construct F so that F is the vertex of the equilateral triangle FDE on DE. | Proposition 1 |
Construct FC, DF and EF. | Postulate 1 |
Notice that DF=EF. | Definition 20 |
Therefore angle DCF equals angle ECF. | Proposition 8 |
Hence DCF and ECF are right. | Definition 10 |