Calculating Angles Between Lines

The video tutorial explains how to calculate the angle between two lines using their gradients, emphasizing that the y-intercept does not affect the angle. It covers the formula for tan theta, the importance of using calculators in degree mode, and the impact of gradient order on the angle's sign. The tutorial also discusses angle domains, converting negative angles to positive, and differentiating between acute and obtuse angles in triangles.

Why does the y-intercept not affect the angle between two lines?

• Because it affects the length of the line.

• Because it alters the angle directly.

• Because it changes the slope of the line.

• Because it only shifts the line up or down.

What is the formula to calculate the angle between two lines using their gradients?

• m1 - m2 divided by 1 plus m1*m2

• m1 + m2 divided by 1 minus m1*m2

• m1 / m2 divided by 1 minus m1*m2

• m1 * m2 divided by 1 plus m1*m2

What happens to the angle calculation if the order of gradients is reversed?

• The angle remains unchanged.

• The angle becomes zero.

• The angle becomes positive.

• The angle becomes negative.

How can a negative angle be converted to a positive one?

• By adding 180 degrees.

• By subtracting 90 degrees.

• By multiplying by -1.

• By dividing by 2.

What is the domain for angles between two lines?

• 0 to 270 degrees

• 0 to 90 degrees

• 0 to 180 degrees

• 0 to 360 degrees

What is the primary goal when calculating angles between lines?

• To determine the slope.

• To solve an equation.

• To measure an angle.

• To find the y-intercept.

When determining the acute angle between two lines, which gradient should be subtracted from which?

• Subtract the first gradient from the second one.

• Subtract the second gradient from the first one.

• Subtract the larger gradient from the smaller one.

• Subtract the smaller gradient from the larger one.

Why is it recommended to sketch a rough diagram when determining angles in a triangle?

• To avoid using the formula.

• To visually identify acute and obtuse angles.

• To ensure the sketch is marked.

• To calculate the exact angle values.

What should be done if the problem asks for an obtuse angle?

• Use the absolute value of the angle.

• Subtract 90 degrees from the angle.

• Add 180 degrees to the angle.

• Multiply the angle by 2.

In a triangle formed by three lines, how many angles can be obtuse?

• All three

• None

• One

• Two