Today I'm going to be teaching a few different things but they all connect in a certain way
Slide: 2
over here on the board we have 2 triangles and we have missing sides !! can you help me with them ?
13
10
?
6
?
4
In order to find a missing side it depends on what side youre looking for. If youre looking for the hypotenuse in this example it would be 6^2+4^2=c^2 or 36+16=c^2. 52=c^2 so, we would use the square root to find c. c=7.2. The hypotenuse can be a decimal if a and b are not perfect squares. To find the leg in the second triangle, it would be 100+b^2=169. b^2=69. If you take the square root of 69 you get b=8.3
Slide: 3
The next part of this is Solving for a side of a triangle using trigonometry. Remember SOHCAHTOA!! S=sin, C= cos, T=tan, O=opposite, A=adjacent, H=hypotenuse
x
19
69°
In this example its different, now we have an angle! but now our sides have names : the tallest side (x) is called a hypotenuse , and the side right next to the angle is called adjacent ,and finally the one OPPOSITE the angle is called opposite . now we try to find what is common between the sides , we have they hypotenuse and the opposite which will make us use the SIN ! put on the calculator the following : 19/sin(69) and we'll get how much is X !
Slide: 4
and now our final part ! a bit harder but i'm sure you can do it !
31
?
13
For this you would use cos. Usually for x we would use something called theta(θ). So for this problem it would be Cosθ=13/31. Since we're finding an angle we have to use inverse cos. θ=cos^-1(13/31). Put the second equation into a calculator and you'll get 65.2 degrees for your missing angle.
Slide: 5
now your turn to solve ! take it slowly step by step and i am sure you'll find the way , if you got stuck just take a quick look at the examples we did before !