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New Zealand
Level 7 - NCEA Level 2

Applications of the Cosine Rule

Interactive practice questions

A triangle has sides of length $13$13 cm, $15$15 cm and $5$5 cm. The largest angle has a size of $x$x$^{\circ}$. Calculate $x$x.

Round your answer to the nearest degree.

Approx 4 minutes
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Find the length of the diagonal, $x$x, in parallelogram $ABCD$ABCD.

Round your answer to two decimal places.

A parallelogram has a side of length $13$13 cm and a diagonal of length $58$58 cm. If the angle between these two is $17^\circ$17° and the length of the other side is $x$x cm, find $x$x.

Round your answer to one decimal place.

Mae went for a bike ride on Sunday morning from Point A to Point B , which was $18$18 kilometers long. She then took a $126^\circ$126° turn and rode from Point B to Point C, which was $21$21 kilometers long. How far was she from her starting point?

Round your answer to two decimal places.



Apply trigonometric relationships, including the sine and cosine rules, in two and three dimensions


Apply trigonometric relationships in solving problems

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