When calculating sides or angles of right angled triangles, it is easiest to use the appropriate trigonometric relation. Finding the value of trigonometric ratios from the tables is learnt easily.
Nowadays of course calculators are able to give accurate values for any degree of tan, sin or cos. It is important to keep in mind the simple algebraic rules for cross multiplication, addition, subtraction while carrying out calculations.
To solve a right angled triangle, we need to find out the unknown sides and the angles with the help of t-ratios.
To find a side, usually we take such t-ratios that involve the unknown sides.
We have taken ÐA because, the side opposite to A is the unknown side. By this simple observation, we have done multiplication instead of division during calculations.
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