1. 9.2 Notes: Solving Right Triangles

2. What does it mean to solve a right triangle?
If we are asked to solve a right triangle, we want to know the values of ALL sides and ALL angles.
A few reminders:
1) The total degrees inside a triangle is 180°.
2) Always check that your calculator is in DEGREE mode!
3) Lower case letters are side lengths, upper case letters are angle measures.

3. Let’s take a look at your calculator:
You will need the following buttons on your calculator to solve for the ANGLE MEASURE:
Tan Sin Cos
When we push one of these buttons and enter a number value, we get the value of the ratio of side lengths.
A) tan 30 B) sin 68 C) cos 127

4. Let’s try some: EX 1: A = 20°, b = 7, find a
EX 2: B = 55°, b = 13, find c

5. EX 3: Solve the triangle when B = 68°, a = 5.
EX 4: Solve the triangle when A = 32°, b = 10

6. Story problems….YAY 
EX 5: A tree casts a shadow 205 feet long. The angle of elevation from the shadow to the sun is 25°. Find the height of the tree.
a) Draw a picture
b) label what you know
c) determine which trig function to use to find the solution.

7. EX 6: You are standing 200 feet from the bases of a redwood tree
EX 6: You are standing 200 feet from the bases of a redwood tree. You estimate the angle of elevation to the top of the tree is 60°. What is the approximate height of the tree?
a) Draw a picture
b) label what you know
c) determine which trig function to use to find the solution.