Comment/Interpretation:
Chapter IV simply describes three angles created by the position of the sword relative to the rest of the body. These angles are useful as they are mentioned at different times in the text.
Translation:
There are three types of angles that a right-handed fencer can create with his feet, body, arm and foil. These are a right-angle, an obtuse angle and an acute angle. You make these as follows:
Imagine a right-hander with his feet in the first position, body straight, right shoulder facing his opponent, foil in hand with his arm stretched out horizontally. He will be forming a right-angle as can be seen in by the letter ‘R’ in the diagram. The obtuse angle is made when he raises his arm and sword as can be seen by the letter ‘O’ in the diagram. The acute angle is made when he lowers his arm below the horizontal – as can be seen by the letter ‘A’.
All the angles are considered relative to the joining of arm to body as can be seen in the diagram (plate 2).
Original Text
CAPITULO IV
De los ángulos
Las especies de ángulos en que el diestro se puede afirmar con sus pies, cuerpo, brazo y florete son tres: recto, obtuso y agudo. Su formacion es como sigue.
Supóngase al diestro en su prirnera posicion de pies, el cuerpo derecho y perfi1ado, con el florete en la mano, y el brazo estirado, formando línea recta horizontal, y le quedará formado el ángulo recto, como se manifiesta en la siguiente estampa letra R.
El obtuso se forma siempre que se levante el brazo y arma, corno en la letra O.
El agudo quando se le inclina hasta abaxo, y debaxo del recto, como lo indica la letra A.
Todos los quales se consideran debaxo del brazo en la union que forma con el cuerpo, como lo manifiesta la siguiente estampa núm. 2.