<p>In the diagram, $ABC$ is a right-angled triangle in which $\angle BAC=90{}^\circ $.  </p>
<p>$AC=16$ cm, $BC=20$ cm, $AB$ is produced to $P$ and $AC$ is produced to $Q$.</p>
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<ol class="abc-list"><li><div class="list-item-paragraph">Calculate $\angle ABC$, correct to $1$ decimal place.</div></li><li><div class="list-item-paragraph">Express each of the following as a fraction, in its simplest form.</div><ol class="i-list"><li><div class="list-item-paragraph">$\sin \angle BCA$,</div></li><li><div class="list-item-paragraph">$\cos \angle BCQ$.</div></li></ol></li></ol>

In the diagram, $ABC$ is a right-angled triangle in which $\angle BAC=90{}^\circ $.  

$AC=16$ cm, $BC=20$ cm, $AB$ is produced to $P$ and $AC$ is produced to $Q$.

Calculate $\angle ABC$, correct to $1$ decimal place.

Express each of the following as a fraction, in its simplest form.

Supplementary Angle Identities: Analyzing Trigonometry Beyond $90^\circ$

Supplementary Angle Identities: Analyzing Trigonometry Beyond $90^\circ$

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