j. 4. Wanting to know the Breadth of a River, I meatured 150 Yards in a straight Line close by one side of it, and at each End of this Line I found the Angles fubtended by the other End, and a Tree close by the other Side of the River, to be 63° and 75 30% What is the Perpendicular Breadth. 5. Ans. 1302 Yards. There is an oblique angled plain Triangle whofe three Sides A B, BC and CA are 60, 100 and 120 refpectively, required the Angles. Ans. ZC 29°56', ZB 93°49' and 6. In the right angled plain Triangle DEF are given D E the Bafe 76, and Hypothenufe DF 90, quere the Angles and Perpendicular. Ans. F 57°37', ZD 32°23' and } 27. In the oblique angled plain Triangle ABC, are given the ZA 37, B 138° and I C 25" and the Side A B 109; required the o-z ther two Sides. Ans. The Side BC 117'1 and AC 1729. 10 8. From a Ship at Sea I obferved a Point of Land to bear E by S, and after failing N E 12 Miles I fet out again and found its bearing to be SE by E. How far was the last Obfervation made from the Point of Land. Ans. 26.07 Miles. 9. Given in the right angled Triangle, ABC the Hypothenufe AC 650 and Perpendicular BC 500, I demand the Angles and Base. 43' and} Ans. The ZA 50° 17', 4C 39°43′ and 10. Wanting to know the Height of a Summer House, which ftood. upon a level Plat of Ground, I measured 60 Yards from its Bottom in a direct Line, and there took the Angle of Elevation of the Top, which I found to be 52,0', and going 80 Yards farther, found the Angle there only 28°; quere the Height of the faid Summer House the Quadrant being placed 6 Feet above the Ground? Ans. 7676 Yards. 11. There is a Triangle ABC, whose Hypothenufe AC is 240, and Base AB 220; what are the Angles. Ans. The 4 A 36,2', and 4 C 53°58'. 12. From the Top of a Ship's Maft, which was 80 Feet above the Water, the Angle of Depreffion of another Ship's Hull upon the Water at a Distance is 20°; what is their Distance. Ans. 219.79 Feet. FINI S. ERRAT A. Page 14 Line 5 for unequal, read equal |