Books Books
If a straight line is perpendicular to each of two straight lines at their point of intersection, it is perpendicular to the plane of those lines.
Elements of Geometry: With Practical Applications to Mensuration - Page 170
by Benjamin Greenleaf - 1868 - 320 pages

## Yale University Entrance Examinations in Mathematics: 1884 to 1898

Mathematics - 1898 - 228 pages
...a polyhedron, a tetrahedron, a prism, a parallelopiped, a pyramid, a cone, a cylinder, a sphere. 2. If a straight line is perpendicular to each of two...of intersection, it is perpendicular to the plane of those lines. 3. If a pyramid is cut by a plane parallel to its base, (a) the edges and altitude...

## Plane and Solid Geometry

James Howard Gore - Geometry - 1898 - 232 pages
...the plane at the greater distance from the foot of the perpendicular. PROPOSITION III. THEOREM. 337. If a straight line is perpendicular to each of two...point of intersection it is perpendicular to the plane of those lines. To prove that BA is perpendicular to EA and hence perpendicular to MN. Make AC equal...

## Entrance Examinations in Mathematics, 1884 to 1898 [with Supplements to 1900]

Yale University - 1898 - 212 pages
...a polyhedron, a tetrahedron, a prism, a parallelepiped, a pyramid, a cone, a cylinder, a sphere. 2. If a straight line is perpendicular to each of two...of intersection, it is perpendicular to the plane of those lines. 3. If a pyramid is cut by a plane parallel to its base, (a) the edges and altitude...

## Ohio Educational Monthly and the National Teacher, Volume 48

Education - 1899 - 658 pages
...have boats, we could not cross. GEOMETRY. 1. If a straight line is perpendicular to each of two other straight lines at their point of intersection, it is perpendicular to the plane of the two lines. 2. The radius perpendicular to a chord bisects the chord and the arc subtended bv...

## Solid Geometry, Volumes 6-9

George Albert Wentworth - Geometry, Solid - 1899 - 246 pages
...SOLID GEOMETRY. PROPOSITION II. THEOREM. 507. If a straight line is perpendicular to each of two other straight lines at their point of intersection, it is perpendicular to the plane of the two lines. Let AB be perpendicular to BC and BD at B. To prove that AB is _L to the plane MN...

## Plane and Solid Geometry

George Albert Wentworth - Geometry - 1899 - 496 pages
...SOLID GEOMETRY. PROPOSITION II. THEOREM. 507. If a straight line is perpendicular to each of two other straight lines at their point of intersection., it is perpendicular to the plane of the two lines. Let AB be perpendicular to BC and BD at B. To prove that AB is -L to the plane MN...

## Plane and Solid Geometry

William James Milne - Geometry - 1899 - 396 pages
...direction with reference to the plane? Theorem. If a straight line is perpendicular to each of two other straight lines at their point of intersection, it is perpendicular to the plane of the two lines. Data : Any two straight lines, as AB and CD, intersecting at E; MN, the plane of...

## The Essentials of Geometry

Webster Wells - Geometry - 1899 - 196 pages
...line can be drawn.] -(§26) Then only one _L can be drawn to MN at P. 400. Cor. I. A straight line perpendicular to each of two straight lines at their point of intersection is perpendicular to their plane. 401. Cor. II. Since E is any point in plane ES, it follows that If...