Applying the law of cosines when given SAS

The video tutorial explains the application of trigonometric laws to solve a triangle problem. Initially, the law of sines is considered but found inapplicable due to insufficient data. The focus shifts to the law of cosines, which is used to calculate a side length. Once the side is determined, the law of sines is applied to find the remaining angles of the triangle. The tutorial provides a step-by-step approach to solving the problem, emphasizing the importance of selecting the appropriate trigonometric law based on available data.

Why can't the Law of Sines be used in this scenario?

• Because all angles are known.

• Because there are no complete ratios available.

• Because the sides are not given.

• Because the triangle is not right-angled.

What is the formula for the Law of Cosines used to find side 'a'?

• a^2 = b^2 - c^2 - 2bc cos A

• a^2 = b^2 + c^2 - 2bc cos A

• a^2 = b^2 + c^2 + 2bc cos A

• a^2 = b^2 - c^2 + 2bc cos A

What is the calculated length of side 'a' after applying the Law of Cosines?

• 10.00

• 25.23

• 21.26

• 15.00

How is angle 'C' calculated using the Law of Sines?

• By using the ratio of side 'a' to angle 'A'.

• By using the ratio of side 'b' to angle 'B'.

• By using the ratio of side 'c' to angle 'C'.

• By using the ratio of side 'a' to angle 'C'.

What is the value of angle 'B' after calculations?

• 25.23 degrees

• 90 degrees

• 115 degrees

• 39.77 degrees