Professor Dave introduces trigonometry, a branch of mathematics dealing with triangles and angles. He explains the concept of angles, coterminal rays, and the use of the coordinate plane. The video transitions from measuring angles in degrees to radians, explaining the historical context and conversion methods. It emphasizes the importance of understanding radians and memorizing key angles for trigonometry.

What branch of mathematics deals with triangles and angles?

• Calculus

• Trigonometry

• Geometry

• Algebra

What do coterminal rays share?

• Same starting point

• Same length

• Same angle

• Same direction

How is a positive angle formed?

• No rotation

• Vertical rotation

• Counter-clockwise rotation

• Clockwise rotation

Why did the Babylonians use 360 degrees in a circle?

• It was a religious belief

• It was a random choice

• It was based on a counting system

• It matched their calendar

What is a radian?

• A unit of length

• A unit of time

• A unit of angle

• A unit of mass

How many radians are in a full circle?

• π radians

• 2π radians

• 4π radians

• 3π radians

What is the radian measure of 180 degrees?

• 2π

• π

• π/2

• 3π/2

How do you convert degrees to radians?

• Subtract π

• Add π

• Multiply by 180/π

• Multiply by π/180

What is the degree measure of 2/3π radians?

• 60 degrees

• 90 degrees

• 120 degrees

• 150 degrees

What is a coterminal angle?

• An angle that shares the same terminal side

• An angle that is a multiple of π

• An angle that is more than 180 degrees

• An angle that is less than 90 degrees