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## Finding the Length of a Side in a Right Angled Triangle

If the angle and the length of a side of a right angled triangle are known we can compute the lengths of the other sides.

### Example 1

Suppose θ = 30º and the opposite side is O = 3. We can make use of the sin θ and Pythagoras Theorem (H2 = O2 + A2) or the tan θ to find the lengths of the hypotenuse and adjacent sides.

For example, Hence .

By Pythagoras Theorem, .

Alternatively, we can find the adjacent side using the tangent function as follows: .

Hence .

### Exercise 4. Find the lengths of the sides of the right angled triangle given the information below.

(Round your answer to 2 decimal places)

 θ = º H = O = A =

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