...together with the line AB form an enclosed figure, and the sum of all the interior angles should be equal to twice as many right angles as the figure has sides, less four right angles. We thus have a check on the observed horizontal angles. It should be carefully...

...? Show that all the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides. (c) Derive the magnitude of an angle of a regular octagon. (d) If the exterior vertical angle of an...

...together with the line AB form an enclosed figure, then the sum of all the interior angles should be equal to twice as many right angles as the figure has sides, less four right angles. We thus have a check on the observed horizontal angles. It should be carefully...

...together equal to four right angles ; and in any convex polygon the sum of the interior angles, together with four right angles, is equal to twice as many right angles as the figure has sides (Euc. I. 32, Cor.) 110 Congruence. CI — If two triangles have two sides and the included angle in...

...perhaps somewhat simpler than, Simson's. 1. The sum of the interior angles of a convex rectilineal figure is equal to twice as many right angles as the figure has sides, less four. For let one angular point A be joined to all the other angular points with which it is not...

...42 COR. 1. All the interior angles of any rectilineal figure, 2 together with four right angles, are equal to twice as many right angles as the figure has sides. 44 COR. 2. If the sides of a rectilineal figure, which has no re-entrant angle, are produced in order,...

...assume the proposition that the interior angles of a convex polygon together with four right angles are equal to twice as many right angles as the figure has sides. Let there be any convex polyhedral angle with V as vertex, and let it be cut by any plane meeting its...

...right angles. = 180' (fig. 2). FIG. 1. FIG. 2. The sum of the interior angles of any rectilineal figure is equal to twice as many right angles as the figure has sides, less 4. Thus, for example, in the irregular pentagon (fig. 3), = 2 x 5 x 90° - 4 x 90° ; FIG. 3....

...triangle whose altitude is 3 inches. SEPTEMBER, 1909 1. The sum of all the interior angles of any polygon is equal to twice as many right angles as the figure has sides, less four right angles. 2. The angle between two chords which intersect within a circle is measured...

...close jK,lygon, which may be summarised as follows. The sum of the ' interior' angles augmented by four right angles is equal to twice as many right angles as i 'he figure has sides. The sum of the ' exterior ' angles diminished by four right angles is equal...