Calculate the size of angle x

A secondary school revision resource for GCSE Maths about higher level length , area and angle calculculation and trigonometry. We have been given the lengths of AC and BC and asked to find angle C. The sine rule is: a over sinA = b over sinB = c over sinC or sinA over a = sinB over b = sinC over c . In your exam, you might be asked to find angles of polygons. This formula comes from dividing the polygon up into triangles using full diagonals.

Next (trust me for the moment) we can re-arrange that into this: x = sin -().

And then get our calculator , key in 0.

Let 4x = the measure of the smallest angle of the triangle. We can now say that 5x and 9x = the degree measures of the remaining angles of the triangle. Angle size calculation refers to the use of geometrical laws and invariants to find out how many degrees an angle is. We can use these rules to answer geometry questions. Work out the answer to each of these questions then click on the button marked Click on this button below to see the correct answer to see whether you are correct.

How to find the size of angles in right-angled triangles using the Sine, Cosine and Tangent ratios. Lines of equal length are marked with dashes. We need to find an angle whose cosine is 0. You should use your calculator like this. Well, we also know that ∠LON = degrees (because perpendicular lines always have an angle measure of 90°).

I can follow this video fine, and know how to do it easily. You must give reasons for your answer. Astronomers use geometry to measure the sizes and distances of planets and nearby stars.

The lines AB and CD are parallel. These formulae can be rearranged to give : cos A = b to . In the diagram, AB is parallel to CDE. Equilateral and isosceles triangles.

A triangle with two sides of equal length and two equal angles. Learn how to find the sum of the interior angles of any polygon. 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: . Mark the two points on the angle that are d length away from the origin. Use the ruler to measure the exact distance between the two points on the angle. In other words, the angle measure is equal . One equation might tell us the sum of the angles of the triangle.

Choose which trig ratio to use. Substitute - Write the trig ratio and .