Right Triangles

1
Section 5-5

• Right Triangles

2
SOH CAH TOA

• Solve the triangle.

Sin 52 12 Tan 52 12 c
b 0.7880 12 1.2799
12 1 c 1 b c
15.2 b 9.4
3
Cos R 10 12 Cos R
0.8333 Cos-1(.8333) 33.6º lt R 33.6
lt T 56.4
r² 10² 12² r² 44 r 6.6
4
Angle of Elevation
This is the angle between the horizontal and the
line of sight!
5
Angle of Depression
25
This is the angle between the horizontal and the
line of sight!
Cos 25 x 900 0.9063
x 1 900 x 815.7
900
25
?
6

• Apothem (a) the measure of a line segment from
  the center of a regular polygon to the mid-point
  of one of its sides

Diameter 8.2 Central lt 360 60
6 60 30
2
Cos30 a 4.1 0.8660 a
1 4.1 a 3.6
7
Homework

• p. 273 15-23 odd, 25-26, 29, 31, 35-38