Ryan+Donovan+12-16

Today in class we went over the quiz or test that we had on monday. Mr. Manning announced the test of Chapter 5b is on friday if there are no school problems. We then went over a hand out we received in class. It was Vectors and Trig Functions. With a 90 degree angle triangle, or a right triangle, the other two angles in the triangle will have to make up the other 90 degrees. The side across from the 90 degree angle is the hypotenuse which is the longest side in the triangle. The other two sides are called the Opposite and the Adjacent, depending on which angle you are trying to find the sides are interchangeable with each other. If one of the angles were to be 20° in a right triangle, no matter how long the sides were all the triangles with a 20° angle would been the same measurement degrees. To find out the lengths of the sides of the triangle you use the Pythagorean Theorem. It states that the (hypotenuse)squared= (opposite)squared+(adjacent)squared. If you know two sides of the triangle then you use this theorem to find the last side. A way to remember how to find a side without using the Pythagorean theorem is SOH CAH TOA. The first one is Sin=opposite/hypotenuse. Second is Cos=Adjacent/Hypotenuse. Third is Tan=opposite/hypotenuse. After we learned all this we then started to go over some examples on the white board. 1) We have a triangle we know one angle is 37°, and the opposite sides length is 8.6 cm. To hypotenuse you would use the equation Cos(37)=8.6/x you then would multiply both sides by x to get, x*Cos(37)=8.6. After multiplying you would then divide by the Cos(37) to have x be alone. x=8.6/Cos(37). x would then equal 10.77 cm. Another example he showed us how to find an angle by using 2 sides. You know the opposite and adjacent side lengths and are solving for hypotenuse. The length of the opposite is 10.2 and adjacent is 9.3. To find out the angle you use the inverse function Tan-1(10.2/9.3) which ends up being 47.6°. The answer to that equation is the degree of the angle you were trying to find.