Civil War Field Fortifications Website

Drawing a five salient star begins with the construction of a regular pentagon. Here the pentagon will have a perimeter of 35 inches and each side will be 5 inches. This pentagon will then be converted into a star by indenting each of the five sides to produce the ten faces of the star.

Draw a right line (AB) that will serve as the base line of the regular pentagon. In this case Line AB should be 1/5 of the perimeter of the pentagon or 7 inches long.

Describe two arcs of circles centered on Points A and B with radii that are equal to one-third (1/3) the perimeter of the pentagon (35 x 1/3 = 11.66) that intersect at D.

Find the  vertices of the angles of the pentagon between Point A and D and B and D by describing arcs of circles with radii equal to the length of the side of the pentagon (7 inches) that are centered on the three known vertices: A and D; B and D. Mark the points where the arcs intersect as Points E and C

Produce right lines to connect successive vertices. These lines form the five sides of the pentagon. All sides should be 7 inches long.

Continue to construct the five salient star by bisecting each side of the pentagon.

Take a distance equal to one-seventh (1/7) the side of the pentagon on the interior of each bisecting perpendicular line. Each side of the pentagon is 7 inches long, so 7 x 1/7 = 1. Perpendiculars K, H, G, F, and L are all 1 inch long.

Lengths of the perpendiculars determine the angular measures of the star's five salient points; increase the length of the perpendicular to decrease the angular measure of the salients. Length of the perpendicular should be about one-fourth (1/4) the side to give the angles a measure of about 60 degrees.

Form the sides of the five salient star by producing right lines from each angle of the pentagon to the interior extremities of collateral perpendiculars; D to K and H, C to H and G, B to G and F, A to F and L, and E to L and K.

Erase all of the construction lines and marks to reveal the 10 sided five salient star.

~ An Instructive Animation Wherein the Foregoing Construction is Visually Explained ~

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