Rounding correctly for the law of cosines

The video tutorial covers solving triangle problems using the law of sines and cosines. It begins with an introduction to isosceles triangles and the purpose of the example. The instructor demonstrates how to apply the law of cosines to find a side length, followed by calculations and error handling. The law of sines is then used to find other side lengths, considering angle properties. The tutorial concludes with final calculations and remarks on triangle properties.

What is the primary purpose of the example discussed in the introduction?

• To solve a problem using only isosceles triangle properties

• To practice using the law of sines and cosines

• To demonstrate the use of a calculator

• To find the area of a triangle

Which formula is used to find the side length 'b' in the triangle?

• b^2 = a^2 + c^2 - 2ac * cos(B)

• b^2 = a^2 + c^2 - 2ac * sin(B)

• b^2 = a^2 + c^2 + 2ac * cos(B)

• b^2 = a^2 - c^2 + 2ac * cos(B)

What is the calculated length of side 'b' after using the law of cosines?

• 7.70

• 8.80

• 6.60

• 5.50

Why is it unnecessary to check for a second case when using the law of sines in this example?

• Because the triangle is isosceles

• Because the triangle has an obtuse angle

• Because the triangle is equilateral

• Because the triangle is right-angled

What is the next step after finding the side length using the law of cosines?

• Calculate the area of the triangle

• Use the law of sines to find other angles

• Check for congruency of the triangle

• Determine if the triangle is right-angled

What is the approximate value of the angle found using the law of sines?

• 34.72 degrees

• 45 degrees

• 30 degrees

• 40 degrees

Why is rounding necessary in the final calculations?

• To avoid errors in the calculator

• To ensure the triangle is isosceles

• To match the precision of the given data

• To simplify the calculations