Transcript Chapter 4 Understanding Trigonometric Functions

Chapter 4
Understanding Trigonometric
Functions
- Special Right Triangles
Language Objectives: We will review Special Right Triangles
by do worksheet 11A
Do you remember
Special Right Triangles?
By yourself draw a square and its diagonal on the paper. What
type of the two triangles formed? Let x represent the measure of
each side of the square and d the measure of the hypotenuse.
According to the Pythagorean Theorem write d in term of x.
Example 4: If the bases on a baseball diamond are 90 feet apart, how far is it
from home plate to second base?
Draw an equilateral triangle on the overhead or chalkboard
with side of length x. Next draw an altitude from one of the
vertices. This altitude bisects the vertex angle and bisects the
opposite side. Use the Pythagorean Theorem to find the
length of the altitude a.
In a 30°-60°-90° triangle, the hypotenuse is twice as long as the
shorter leg, and the longer leg is
times as long as the
shortest leg.
Example 6: Solve for a and b
Example 7: The perimeter of an equilateral triangle is 9 cm. What is the
length of the
altitude?
Exit directions 
Do: From a group of 3 then complete the Worksheet 11A.
Put: In box No. 3
Finish By: 10.40
When done do: Find other proofs of the Pythagorean
Theorem.