...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 noted that the included...

...which says, that " the interior angles of any straight lined figure together with four right angles are equal to twice as many right angles as the figure has sides." The most common of the regular polygons used in engineering designs are the pentagon (five-sided),...

...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 noted that the included...

...? 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...

...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 connected...

...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...

...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...

...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,...

...to two right angles. 0- (fig. 2). Fm. 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. or generally,...

...correct unless you are expressly asked to do so. 1. Prove that the sum of all the angles of any polygon is equal to twice as many right angles as the figure has sides less four. 2. Prove that in the same circle, or in equal circles, equal arcs arc subtended by equal chords. 3....