## Plane and Spherical Trigonometry |

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angle ends angle opposite Applying base line becomes known blog a log circle circular measure Construct the angles cos a cos cos² cosec cosine cotangent Dividing draw a perpendicular equation feet Find the angle Find the area Find the distance formulas 19 fourth quadrant Functions of Multiples geometry greater than 90 hypotenuse initial side interchanging letters inverse functions latitude log blog log cos log cot log sin miles multiple of 90 Multiplying numerator Napier's rules negative numerator and denominator oblique angle observer's plane polar triangle positive Problems projection on XX Prove quadrant sec radial distance radians radius ratio right angle right spherical triangle right triangle secant second quadrant Show side opposite sin A cos sin A sin sin¹ sin² sine formula Solve spherical trigonometry tan² tangent terminal side third quadrant triangles OPD triedral angle trigonometric functions vertex whence

### Popular passages

Page 61 - The sum of any two sides of a triangle is to their difference, as the tangent of half the sum of the angles opposite to those sides, to the tangent of half their difference.

Page 62 - B)' (51) 116. In any triangle, the square of any side is equal to the sum of the squares of the other two sides, minus twice their product into the cosine of their included angle.

Page 68 - Construct a triangle, having given two sides and the angle opposite one of them (a, b, /A).

Page 9 - A unit of plane angular measurement equal to the angle at the center of a circle subtended by an arc equal in length to the radius.

Page 28 - ... foot of the post is 8° 32' 15". Calculate the height of the telegraph post and its distance from the observer. 13. A man in a balloon, when it is one mile high, finds the angle of depression of an object on the level ground to be 35° 20', then after ascending vertically and uniformly for 20 min., he finds the angle of depression of the same object to be 55° 40'. Find the rate of ascent of the balloon in miles per hour. 14. A man observes the elevation of a mountain top to be 15°, and after...

Page 55 - The logarithm of a quotient equals the logarithm of the dividend minus the logarithm of the divisor.

Page 46 - CD is drawn from the vertex of the right angle to the middle point of AB, angle ACD equals 60°.

Page 28 - What is the height of a flagpole if at a horizontal distance of 200 feet from the foot of the pole the angle of elevation of its top is 19° 28