Trigonometry (10th Edition)

Published by Pearson
ISBN 10: 0321671775
ISBN 13: 978-0-32167-177-6

Chapter 7 - Review Exercises - Page 344: 29

Answer

The height of the tree is 53.2 feet

Work Step by Step

Let C be the point at the top of the tree. Let D be the point where the angle of elevation is $27.2^{\circ}$ Let E be the point level with point D which is directly under the tree. Then points CDE form a triangle. We can find the angle $C$: $C+D+E= 180^{\circ}$ $C = 180^{\circ}-D-E$ $C = 180^{\circ}-27.2^{\circ}-90^{\circ}$ $C = 62.8^{\circ}$ Let C be the point at the top of the tree. Let B be the point at the bottom of the tree Let A be the point where the angle of elevation is $14.3^{\circ}$. Then from point A, the angle between the bottom of the tree and the top of the tree is $27.2^{\circ}-14.3^{\circ} = 12.9^{\circ}$ The points ABC form a triangle. We can use the law of sines to find $h$, the height of the tree: $\frac{h}{sin~12.9^{\circ}} = \frac{212~ft}{sin~62.8^{\circ}}$ $h = \frac{(212~ft)~sin~12.9^{\circ}}{sin~62.8^{\circ}}$ $h = 53.2~ft$ The height of the tree is 53.2 feet
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.