Propositions 48—84

elements : 37

Proposition 10.54

If an area be contained by a rational straight line and the first binomial, the side of the area is the irrational straight line which is called binomial.

Proposition 10.55

If an area be contained by a rational straight line and the second binomial, the side of the area is the irrational straight line which is called a first bimedial.

Proposition 10.56

If an area be contained by a rational straight line and the third binomial, the side of the area is the irrational straight line called a second bimedial.

Proposition 10.57

If an area be contained by a rational straight line and the fourth binomial, the side of the area is the irrational straight line called major.

Proposition 10.58

If an area be contained by a rational straight line and the fifth binomial, the side of the area is the irrational straight line called the side of a rational plus a medial area.

Proposition 10.59

If an area be contained by a rational straight line and the sixth binomial, the side of the area is the irrational straight line called the side of the sum of two medial areas.

Proposition 10.60

The square on the binomial straight line applied to a rational straight line produces as breadth the first binomial.

Proposition 10.61

The square on the first bimedial straight line applied to a rational straight line produces as breadth the second binomial.

Proposition 10.62

The square on the second bimedial straight line applied to a rational straight line produces as breadth the third binomial.

Proposition 10.63

The square on the major straight line applied to a rational straight line produces as breadth the fourth binomial.

Proposition 10.64

The square on the side of a rational plus a medial area applied to a rational straight line produces as breadth the fifth binomial.

Proposition 10.65

The square on the side of the sum of two medial areas applied to a rational straight line produces as breadth the sixth binomial.

Proposition 10.66

A straight line commensurable in length with a binomial straight line is itself also binomial and the same in order.

Proposition 10.67

A straight line commensurable in length with a bimedial straight line is itself also bimedial and the same in order.

Proposition 10.69

A straight line commensurable with the side of a rational plus a medial area is itself also the side of a rational plus a medial area.

Proposition 10.70

A straight line commensurable with the side of the sum of two medial areas is the side of the sum of two medial areas.

Proposition 10.71

If a rational and a medial area be added together, four irrational straight lines arise, namely a binomial or a first bimedial or a major or a side of a rational plus a medial area.

Proposition 10.72

If two medial areas incommensurable with one another be added together, the remaining two irrational straight lines arise, namely either a second bimedial or a side of the sum of two medial areas.

Proposition 10.73

If from a rational straight line there be subtracted a rational straight line commensurable with the whole in square only, the remainder is irrational; and let it be called an apotome.

Proposition 10.74

If from a medial straight line there be subtracted a medial straight line which is commensurable with the whole in square only, and which contains with the whole a rational rectangle, the remainder is irrational. And let it be called a first apotome of a medial straight line.

Proposition 10.75

If from a medial straight line there be subtracted a medial straight line which is commensurable with the whole in square only, and which contains with the whole a medial rectangle, the remainder is irrational; and let it be called a second apotome of a medial straight line.

Proposition 10.76

If from a straight line there be subtracted a straight line which is incommensurable in square with the whole and which with the whole makes the squares on them added together rational, but the rectangle contained by them medial, the remainder is irrational; and let it be called minor.

Proposition 10.77

If from a straight line there be subtracted a straight line which is incommensurable in square with the whole, and which with the whole makes the sum of the squares on them medial, but twice the rectangle contained by them rational, the remainder is irrational: and let it be called that which produces with a rational area a medial whole.

Proposition 10.78

If from a straight line there be subtracted a straight line which is incommensurable in square with the whole and which with the whole makes the sum of the squares on them medial, twice the rectangle contained by them medial, and further the squares on them incommensurable with twice the rectangle contained by them, the remainder is irrational; and let it be called that which produces with a medial area a medial whole.

Proposition 10.79

To an apotome only one rational straight line can be annexed which is commensurable with the whole in square only.

Proposition 10.80

To a first apotome of a medial straight line only one medial straight line can be annexed which is commensurable with the whole in square only and which contains with the whole a rational rectangle.

Proposition 10.81

To a second apotome of a medial straight line only one medial straight line can be annexed which is commensurable with the whole in square only and which contains with the whole a medial rectangle.

Proposition 10.82

To a minor straight line only one straight line can be annexed which is incommensurable in square with the whole and which makes, with the whole, the sum of the squares on them rational but twice the rectangle contained by them medial.

Proposition 10.83

To a straight line which produces with a rational area a medial whole only one straight line can be annexed which is incommensurable in square with the whole straight line and which with the whole straight line makes the sum of the squares on them medial, but twice the rectangle contained by them rational.

Proposition 10.84

To a straight line which produces with a medial area a medial whole only one straight line can be annexed which is incommensurable in square with the whole straight line and which with the whole straight line makes the sum of the squares on them medial and twice the rectangle contained by them both medial and also incommensurable with the sum of the squares on them.