EXP. 1 Hyp. 1.

2.

2 Concl.

DEM. 1 Hyp.

2 P. 32.

3 D. 1. 2.

4 Hyp.

5 P. 15. C. 2.

6 Concl.

COR. II. All the ext. angles of any rectilineal figure are together equal to four rt. angles.

COR. III. If two triangles ABC, ADE have two angles of the one ABC, ACB, respectively equal to two angles of

the other, AED, ADE; then the third angle of the one, BAC, shall be equal to the third angle of the other, DAE.

DEM. 1| Hyp.

2 P. 32.

3 P. 32.

4 Sub.

5 Ax. 3.

>

USE.

BROP. XXXIII. THEOR. The st. lines which join the extremities of two equal and parallel st. lines towards the

PROP. XXXIV. THEOR. The opposite sides and angles of parallelograms are equal to one another, and the d

bisects them; that is, divides them into two equal parts.

DEM. P. 29. 26. 4. Ax. 2.

PROP. XXXV. THEOR. Parallelograms upon the same base and between the same parallels are equal, or rather

equivalent, to one another.

DEM. P. 34. Ax. 6. 1. 3. P. 29. 24.

EXP. 1 Hyp. 1.

2.

2 Concl.

CASE I. Sup.

DEM 1 P. 34.

2 Ax. 6.

CASE II. Sup.

DEM. 1 H. P. 34.

2 H. P. 34.

3 Ax. 1.

44d. or Sub.