A synopsis of practical mathematics; Containing plain trigonometry, mensuration of heights, distances, surfaces, and solids surveying of land, ... numbers, and of sines and tangents. For the u

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1799 Excerpt: ...to sind the length of its side. x = the side of the nonagon. Half the angle of a nonagon is 700, of which the tan gent is 2 7474774--b. The half sum of the sides is--bx and the perpendicular falling from the centre is---224 90. cjb. Exam-The area of a nonagon is 10,000 square feet, -what is the length of its side? Ans. 40.214 feet. a =10,000 o = 24.7272966 Then./if--Jt000--= 40.214 feet. 9 24.7272966 9. The area of a regular decagon being given, to sind the length of its side. The angle of a decagon is 1440, its half 7 20, whose bx tangent is 3.0776835--b.--=the perpendicular as before. The half sum of the sides is 5. Then-= a and '= also =yH Exam-The area of a decagon is 50,000 square feet, -what is the length of its side? Ans. 80.208 feet. a =50000. 5= 15.3884175. 100000, = 5 =64 3.4106 15.3884175 --and x = V 6433.4106--80.2t8. 10. The area of an undecagon being given, to find the "length of its side. 11b Exam. The area of an undergon is 5280 square yards, what is the length of its fide? Ans. 23.747 yards.,1=5280. 11 = 37.4565653 211 20 then x = =563.8530 and =563.8530 37.4565653 33 3 5 = 23.747 yards. 11. The area of a dodecagon being given, to find the length of its fide. Let a = the area, =the fide as before. Half the angle of a dodecagon is 750w hose tangent is 3.7320508--The perpendicular =, and 6x is the half sum of tfee sides. 6xX--=3 bx--a x1--and x = / 2 0 3 3 Exam. Let the area of a dodecagon be 360 square-yards, what is the length of its fide? Aris. 5.67043 yards.. 3Co 11.19615.24 J ' i 12. To reduce ar.y quadrilateral figure ABCD to a triangle. Fig. 67. Join AC; through B draw BE parallel to AC; produce DC to E, and join AE; then the triangle AED is 1-qual to the given figure ABCO. 13. T- 13. To reduce any five fi...