Degree and Radian Measure 2

Hi this is Ivern Casaclang.
In today's class we learned that two positive angles are:

• Supplementary - if the sum of their measures is 180° or π 
• Complementary - if the sum of their measures is 90° or π/2
  

Remember: 

θ must be in radians to use any of the following formulas 

s = θr           or     s/r = θ      or     s/θ = r

area of sector = θ × r² / 2

You should know that : 

s = arc length

r = radius

θ = central angle

Examples: 

Homework : 

Exercise 1, Questions 3 -5, 11, 12

Sector of A Circle Worksheet