6.2.2 – Minute/Second Notation, Applications

1. 6.2.2 – Minute/Second Notation, Applications

2. Take out your unit circle

3. Before the use of calculators, had to use “trig tables” • And, in many applications, certain angle values are expressed in one form known as DMS notation • DMS = degree, minute, second notation

4. DMS • In the context of DMS angle measure: • 1’ = one minute = (1/60) (10) • 1’’ = one second = (1/60) 1’ = (1/3600)(10) • Example. Convert 140 37’23’’ to degrees.

5. Example. On a GPS, a particular angle is measured as 39056’24’’. Convert the angle to degree measure and then radians.

6. Applications • Many of you have been exposed to some applications already • Mainly, can be helped in determining data/missing information from right triangles in various forms • Missing heights • Missing lengths • Unknown angle measures

7. Example. A particular ladder manufacturer recommends the ladder be tilted at an angle of 750. If the ladder is 18.5 feet tall, how far should the ladder be positioned away from a wall?

8. Example. A building inspector is checking the height of a new parking garage ramp. He cannot walk up the new ramp, but he determines the distance from the base of the ramp to the edge is 40 ft with an angle of 150. Determine the height of the new ramp.

9. Surveyor Problem • Lets say you know the angle of approach, but you do not know the height of the object OR the distance of how far you are away from the object • What to do?!?!?!

10. If we know the angles, and the distance from a particular spot we need to measure from: • h = d/(cot(a) x cot(b)) • d = distance from point of interest • a = angle measure 1 b = angle measure 2

11. Example. You discover a hawk’s nest outside. You want to determine the height the nest is at, but cannot get near the base of the tree. The initial angle you measure is 400. After getting 25 feet closer, the same angle is now 52.50. What is the height of the nest?

12. Assignment • Pg. 483 • 39-71 odd