Triangle Angle Relationships and Rules

The video tutorial explains how to find the smallest and largest angles in a triangle by identifying the sides opposite these angles. It introduces trigonometric notation for sides and angles, and demonstrates the use of the cosine rule to find an angle when three sides are known. The tutorial also covers the sine rule for finding angles when a side and its opposite angle are known. Finally, it calculates the middle angle using the angle sum property of triangles.

What is the smallest angle in a triangle opposite to?

• The largest side

• The smallest side

• The hypotenuse

• The middle side

Which side is the largest angle in a triangle opposite to?

• The smallest side

• The middle side

• The longest side

• The hypotenuse

In trigonometry, what notation is used for an angle?

• Greek letter

• Uppercase letter

• Lowercase letter

• Number

When is the cosine rule used in a triangle?

• When all angles are known

• When one side and one angle are known

• When three sides are known

• When two sides and an angle are known

What is the first step in using the cosine rule?

• Add all sides

• Subtract b^2 and c^2 from both sides

• Multiply all sides

• Divide by 2

What is the value of small a in the example?

• 6.5

• 5.39

• 8

• 7.81

What rule is used to find the largest angle when enough information is available?

• Pythagorean theorem

• Tangent rule

• Sine rule

• Cosine rule

What is the first step in using the sine rule?

• Cross multiply

• Invert both sides

• Add all angles

• Subtract angles

What is the calculated largest angle in the example?

• 68.4 degrees

• 39.8 degrees

• 71.8 degrees

• 50 degrees

How do you find the middle angle in a triangle?

• Divide the largest angle by 2

• Subtract the known angles from 180

• Subtract the smallest angle from 180

• Add all sides