Geometry
1.
Find the unknown side length.
65
72 x
Find the value of x.
3.
20 x
5.
3 x
2
12
Name_________________________
2.
Given the side lengths of a triangle, classify it as right, acute, or obtuse.
26, 10, 17
4.
6.
4 x
25 x
9
20

Notes
Special Right Triangles
Today: We will understand special right triangles and how they are used.
By the end of today: You will be able to identify the angles and sides in s 30, 60, 90 triangle and a 45,45,90 triangle.
Theorem - 45°-45°-90° Triangle Theorem hypotenuse = leg  2
1.
Examples
Find the length of the hypotenuse.
45

8
Find the lengths of the legs in the triangle.
5 2
3. x x
2.
4. x
45

3 2
10 x x x 2
45
 x
3 2

Theorem - 30°-60°-90° Triangle Theorem
60

2x x longer leg = shorter leg  3
Examples
Find the value(s) of the variable(s).
5. y
60
 x
A
6.
30

3
60
 x 3
30

30

9 x
30

7. The logo on a recycling bin resembles an equilateral triangle with side lengths of 6 centimeters.
What is the approximate height of the logo?
8. Fill in the chart with the missing lengths.
C
60

B