Download Name:___________________________________ Date:________Period:_______ The legs of a right triangle are 18 and 24... Chapter 8: Basic Trigonometry

Name:___________________________________
Date:________Period:_______
Chapter 8: Basic Trigonometry
Topic 1: Introduction to Trigonometry
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The legs of a right triangle are 18 and 24 inches. Find the hypotenuse.
Trigonometry is the branch of mathematics that studies the relationship between the
______________ and _______________ of a triangle.
*Trig
is for __________ Triangles
We will be looking at the triangle from the perspective of the given angle. (x or θ)
We have to label our triangle with 3 words
associated with our trig functions:
____________, ____________and
____________
The sides get labeled by their relationship with the given angle.
Label the triangles below:
To solve triangle problems for the lengths of sides or values of angles, we use our trig functions
Recall: Soh Cah Toa
Find the value for each of the trigonometric ratio.
So, how do I know which to use?
Example 1: In right triangle ABC with the right angle at C, the hypotenuse length AB=15 and
measure angle A=35˚. Find leg length BC to the nearest tenth
Example 2 : Find the length of x.
INDEPENDENT PRACTICE
Directions: Find the value of each trigonometric ratio.
1) a) Find the sin A
b) Find the cos A
2) a) Find the tan A
b) Find the cos A
To solve for an ANGLE, we must use _______________ _______________!
Example 3: In right triangle ABC, leg length BC=15 and leg length AC=20. Find angle A to the
nearest degree.
Directions: Find the missing side. Round to the nearest tenth if necessary.
3)
4)
5)
6)
Directions: Find the measure of the indicated angle to the nearest degree.
7)
9) In right triangle ABC, leg AB = 11
and leg BC = 4.4, find the measure
angle C.
8)
10) In right triangle ABC, leg AC = 10
and leg BC = 11.9, find the measure of
angle A.