I'm reading SL Loney's plane trigonometry book and I arrived at a theorem saying : "the length of the circumference of a circle always bears a constant ratio to its diameter."
Now, in this proof he uses two propositions from the book VI of Euclid. Now, am I supposed to be reading these proposition and all the definitions,axioms,etc. or I can take them for granted and continue reading the theorem without them ? How is it done, in your opinion?(I'm new to the domain of proofs ^^)