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Grade 10

Applications of the Cosine Law

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

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.

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Solve problems involving the measures of sides and angles in acute triangles

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