SOLVING TRIGONOMETRY QUESTIONS (PART A) USING CASIO CALCULATOR (fx-991ES PLUS, NATURAL- V.P.A.M)

TRIGONOMETRY Angles: When a straight line fixed at a point, rotates; it sweeps out an angle that can be measured using two conventions of a unit angle. One convention divides the angle in a circle into 360 equal parts, each part called a degree. The other convention uses the radius of a circle to define a unit as the angle subtended by an arc of the circle of length equal to the radius. By convention, a straight line rotating through a full angle and returning to its starting position is said to have rotated through 360 degrees written as 360°, where each degree is subtended into 60 minutes (60') and each minute further subdivided into 60 seconds (60'') While a straight angle is half of 360° i.e. 180° and a right angle is half of 180° i.e. (90°). Any angle less than 90° is called an ACUTE ANGLE and any angle greater than 90° is called an OBTUSE ANGLE. 1° = 60' i.e One degree = 60 minutes 1° = 60" i.e One minute = 60 seconds Conversion of Angles in Degrees: An angle that is measured in degrees, minutes and seconds can be converted to a decimal degree (format) and vice versa as follows: Example 1: Convert 54°18'42" to decimal degree format. Solution: 54°18'42" = 54"+ (18/60)° + (42/60×60)° = 54+0.3+0.0116667" = 54.3116667° =54°18'42 ≈ 54.312° (to 3dp) Example 2: Convert 236°59'10" to decimal degree format. Answer = 236.983611° ≈ 236.984° (to 3dp) Watch the video for explanation ✍️... Do well to subscribe, hit the like button, ask questions. The Lord Is Our Strength!