...cc makes with EFtwo angles together equal to two right angles. But these two angles are (by def. 92) the angles of inclination of the two planes. Therefore...other, which are together equal to two right angles. Corol. In like manner, it may be demonstrated, that planes which intersect, have their vertical or...

...makes with EF two angles together equal to two right a.igles. But these two angles are (by def 91) the angles of inclination of the two planes. Therefore...other, which are together equal to two right angles. Coral. In like manner it may be demonstrated, that planes which intersect, have their vertical or opposite...

...these two angles are (by def. 91) the angles of inclination of the two planes. Therefore the two pianos make angles with each other, which are together equal to two right angles. Carol. In like manner it may be demonstrated, that planes which intersect, have their vertical or opposite...

...together equal to two right angles. But these two angles are (by def. 92) the angles of inclina» tion of the two planes. Therefore the two planes make angles...other, which are together equal to two right angles. Carol. In like manner, it may be demonstrated, that planes which intersect have their vertical or opposite...

...with the line FG two angles together equal \ I \ to two right angles. But these two angles are (Defin. 3.) the angles \ \ of inclination of the two planes....other, which are together equal to two right angles. COROLLARY. It may be demonstrated in the same manner that planes which intersect each other have their...