Recall
Test (to classify a triangle by its angles)
c2 = a2 + b2
c2 > a2 + b2
c2 < a2 + b2
Examples:
1. 9, 17, 12
2. 18, 20.1, 9.6
3. 18, 24, 30
Warm Up: Find the area of the parallelogram.
7
6
10
5-4 SPECIAL RIGHT TRIANGLES
Objective: Use properties of 45-45-90 and
30-60-90 triangles.
l
l
5.4 Special Right Triangles
Another name for an isosceles right triangle is a 45°­45°­90° triangle.
A 45°­45°­90° triangle is one type of special right triangle. You can use the Pythagorean Theorem to find a relationship among the side lengths of a 45°­45°­90° triangle.
5-6
Finding Side Lengths in a 45°­ 45º­ 90º Triangle
Find the value of x. Give your answer in simplest radical form.
45
x
Find the missing sides.
Find the value of x. Give your answer in simplest radical form.
You Try:
Find the value of x. Give your answer in simplest radical form.
Find the value of x. Give your answer in simplest radical form.
1. Find x.
13
x
A. x = 13
B. x = 13√2
C. x = 13.2
D. x = 13/√2
2. Find x.
A. 3√2
3√2
B. √2
45°
x
C. 3/√2
D. 3
3. Find x.
A. 5√2
x
45°
5√2
B. 5
C. 10
D. 5/√2
HW # 49
p. 266­67 # 1,2,5,6,10,11,20,22