Math 10 – Week 7

This week the class learned about trigonometry we learned how to solve the angles and the side lengths. We are currently with right angle triangles where one of the angles is  90° and the two other angles add up to  90° making the whole triangle add up to 180°. This following week we learned how to find the missing angles or side lengths when one is not apparent. The formulas that help figure out the missing side length or angle are as stated S = \frac{O}{H} or Sine = \frac{Opposite}{Hypotenuse} (SOH), C = \frac{A}{H} or Cosine = \frac{Adjacent}{Hypotenuse} (CAH), and  T = \frac{O}{A} or Tangent = \frac{Opposite}{Adjacent} (TOA). SOH CAH TOA is a very useful expression that helps us remember the needed formula. Labelling the triangles sides (Opposite, Adjacent, Hypotnuse) is the most important and helpful thing to do. The another essential thing is to know the reference angle as it makes up what sides are the opposite or the adjacent, because the hypotenuse is directly across from the right angle.

Finding the side length 

To find the side length you need to take it one step at a time. FIRST you need to label the sides (Opposite, cosine, sine) THEN locate the needed sides. One will be the side you need and the other will be the side have. In this case I had the hypotenuse, and I needed the the opposite side. Then I put sin because the first letter was S in SOH and the reference, and in this case “X” was the opposite angle and the hypotenuse was 64. To isolate the variable you multiply the hypotenuse by itself then plug that in your calculator.

When the side length is the denominater

 

To find the side length when the missing length is the denominater is actually not difficult. You do everything in the beginning like the regular side length. Like label the sides, find the reference point, etc. Though you now have to put the length you have up top as the numerator. So you divide the known side length by the (Sin, cosine or Tangent) angle.

 

How to find the angle 

 

To find the angle is simple as well as you just again label the sides, find the reference angle, etc. But this time. For example, cos x is put as the reciprocal.