Finding Angles If you need to find the size of an angle, you need to use the version of the Cosine Rule where the cos A is on the left: You will need to know at least one pair of a side with its opposite angle to use the Sine Rule. We appreciate any comments you have about Step-Up Section 4. Practice Questions Work out the answer to each question then click on the button marked to see if you are correct. You are commenting using your Google account. Fill in your details below or click an icon to log in: Solution to Problem 2:

Since these pages are under development, we find any feedback extremely valuable. Finding Sides If you need to find the length of a side, you need to know the other two sides and the opposite angle. By continuing to use this website, you agree to their use. The question involves angles. Angle of elevation and depression. Fill in the values you know, and the unknown angle: Explain, concretely, pictorially or symbolically, whether zero, one or two triangles exist, given two sides and a non-included angle.

Solve a problem involving the sine law that requires the manipulation of a formula. Cosinea Sides Example Work out the length of x in the diagram below: There were 0 questions which you didn’t attempt or check. We appreciate any comments you have about Step-Up Section 4.

Solve Right Triangles Part 3 4. Find the height h of the building round your answer to the nearest unit. Thf Questions Work out the answer to each question then click on the button marked to see if you are correct. To the nearest degree, at what angle should a team turn in order to go from the first checkpoint to the second checkpoint?

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Sometimes more than one technique from the formula table at the top of this page can be used to solve la trig problem, but you will want to choose the most efficient and easiest method to save time. These examples illustrate the decision-making process for a variety of triangles: The distance between points A and B is 30 meters.

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## Solving Triangles – using Law of Sine and Law of Cosine

Step 1 Start by writing out the Cosine Rule formula for finding angles: After finding x you have enough information to use trigonometry in the right-angled triangle above the dotted line. We do not know a side and its opposite angle.

Fill in your details below or click an icon to log in: The triangle is right-angled. If you were solvig that the lzw worked correctly, please click the button on the right.

Solve triangle problems using the sine law.

## Sine Law to Solve Triangle Problems

Finding Angles If you need to find the size of an angle, you need to use the version of the Sine Rule where the angles are on the top: To find lage more, including how to control cookies, see here: Solve a problem involving the cosine law that requires the manipulation of a formula.

Find the unknown side or angle in each of the following diagrams: Solve the resulting equation to find the sine of the unknown angle: The triangle to the right of the dotted line is right-angled, so use the appropriate trig ratio sin, cos or tan.

The triangle is right-angled, and the question involves angles, so we need to use trigonometric ratios.

What to do in this Unit: Solution Jessica is creating a pattern for a piece of stained glass. There were 0 questions where the answer was left incorrect.

# Law of Sines and Law of Cosines calculator

Solve the triangle ABC by finding angle B and sides a and b. Geometry Tutorials, Problems and Interactive Applets. Formulae You Should Know You should already know each of the following formulae: Therefore we use Pythagoras’s Theorem. The question does not involve angles.