Trigonometric Concepts and Angles

The video tutorial explains the unit circle and triangle ABD, focusing on calculating the radian measure of angle ABD. It explores the properties of isosceles triangles and uses the Pythagorean Theorem to find side lengths. The tutorial concludes by finding the sine, cosine, and tangent of pi/4 using the unit circle definition of trigonometric functions.

What is the measure of angle BAD in radians?

• pi/2

• pi

• pi/4

• pi/6

What is the sum of the interior angles of a triangle in radians?

• pi

• 2pi

• pi/2

• 3pi/2

If two angles in a triangle are equal, what type of triangle is it?

• Equilateral

• Scalene

• Right

• Isosceles

What is the length of each leg in the isosceles right triangle ABD if the hypotenuse is 1?

• 1

• sqrt(2)/2

• sqrt(3)/2

• 1/2

What is the principal root of 1/2?

• 1/2

• 1

• sqrt(3)/2

• sqrt(2)/2

What is the sine of pi/4 radians?

• 1

• 0

• 1/2

• sqrt(2)/2

What is the cosine of pi/4 radians?

• 1

• sqrt(2)/2

• 0

• 1/2

What is the tangent of pi/4 radians?

• 0

• 1

• sqrt(2)

• 1/2

What is the relationship between the sine and cosine of pi/4 radians?

• Sine is zero

• Sine is half the cosine

• Sine equals cosine

• Sine is double the cosine

What is the slope of the line formed by angle pi/4 in the unit circle?

• 0

• 1

• 1/2

• sqrt(2)