Sine Rule and Angle Calculations

The video tutorial explains the sine rule for non-right angled triangles, providing examples of how to use it to find missing lengths and angles. It covers both acute and obtuse angles, demonstrating the process of using the sine rule formula and calculator to solve problems. The tutorial includes practice questions for viewers to try on their own.

What is the sine rule used for in non-right angled triangles?

• To find the area of the triangle

• To find a missing length or angle

• To determine if the triangle is equilateral

• To calculate the perimeter of the triangle

Which of the following is a version of the sine rule for calculating lengths?

• a times sine A equals b times sine B

• sine A over a equals sine B over b

• a over sine A equals b over sine B

• a over b equals sine A over sine B

In the sine rule, what do the lowercase letters represent?

• Angles

• Lengths

• Areas

• Perimeters

In the first example, what is the value of x to two decimal places?

• 13.45

• 15.68

• 12.53

• 14.97

In the second example, what is the value of x to two decimal places?

• 8.45

• 7.45

• 6.78

• 9.32

In the third example, what is the value of angle x to two decimal places?

• 34.63 degrees

• 45.12 degrees

• 37.15 degrees

• 51.78 degrees

What is the process to find an obtuse angle using the sine rule?

• Multiply the acute angle by 2

• Add 90 to the acute angle

• Divide the acute angle by 2

• Subtract the acute angle from 180

In the final example, what are the two possible values of angle x?

• 51.78 degrees and 128.22 degrees

• 75.76 degrees and 104.24 degrees

• 34.63 degrees and 145.37 degrees

• 82.71 degrees and 97.29 degrees