Questions: Clear my choice
(triangle ABC) is a right triangle: If angle A=32 degrees, angle B=90 degrees, AC=9 and AB=5, choose the expression used to find BC.
Select one:
a. 5 tan 32 degrees
b. 9/sin 32 degrees
c. 9/tan 58 degrees
d. 5 cos 58 degrees
Use your calculator to find the measure of angle. (Round your answer to the nearest degree.).
Transcript text: Clear my choice
( (triangle $A B C($ ) is a right triangle: If $\angle A=32^{\circ}, \angle B=90^{\circ}, A C=9$ and $A B=5$, choose the expression used to find $B C$.
Select one:
a. $5 \tan 32^{\circ}$
b. $\frac{9}{\sin 32^{\circ}}$
c. $\frac{9}{\tan 58^{\circ}}$
d. $5 \cos 58^{\circ}$
Use your calculator to find the measure of angle. (Round your answer to the nearest degree.).
Solution
Solution Steps
To find the length of side \( BC \) in the right triangle \( \triangle ABC \), we can use trigonometric ratios. Given that \( \angle A = 32^\circ \) and \( \angle B = 90^\circ \), we can use the tangent function, which relates the opposite side to the adjacent side in a right triangle. The correct expression to find \( BC \) is \( AB \cdot \tan(\angle A) \).
Solution Approach
Identify the given values: \( \angle A = 32^\circ \), \( \angle B = 90^\circ \), \( AC = 9 \), and \( AB = 5 \).
Use the tangent function: \( \tan(\angle A) = \frac{BC}{AB} \).
Solve for \( BC \): \( BC = AB \cdot \tan(\angle A) \).
Step 1: Identify the Given Information
We are given a right triangle \( \triangle ABC \) with:
\( \angle A = 32^\circ \)
\( \angle B = 90^\circ \)
\( AC = 9 \)
\( AB = 5 \)
We need to find the expression used to determine \( BC \).
Step 2: Determine the Relationship
Since \( \angle B = 90^\circ \), \( \angle C = 58^\circ \) (because \( \angle A + \angle C = 90^\circ \)).
Step 3: Use Trigonometric Ratios
To find \( BC \), we can use the trigonometric ratios involving the given sides and angles.
Option a: \( 5 \tan 32^\circ \)
This option uses the tangent function:
\[ \tan 32^\circ = \frac{BC}{AB} \]
\[ BC = AB \cdot \tan 32^\circ \]
\[ BC = 5 \cdot \tan 32^\circ \]
Option b: \( \frac{9}{\sin 32^\circ} \)
This option uses the sine function:
\[ \sin 32^\circ = \frac{BC}{AC} \]
\[ BC = AC \cdot \sin 32^\circ \]
\[ BC = 9 \cdot \sin 32^\circ \]
Option c: \( \frac{9}{\tan 58^\circ} \)
This option uses the tangent function:
\[ \tan 58^\circ = \frac{BC}{AC} \]
\[ BC = AC \cdot \tan 58^\circ \]
\[ BC = 9 \cdot \tan 58^\circ \]
Option d: \( 5 \cos 58^\circ \)
This option uses the cosine function:
\[ \cos 58^\circ = \frac{AB}{BC} \]
\[ BC = \frac{AB}{\cos 58^\circ} \]
\[ BC = \frac{5}{\cos 58^\circ} \]
Step 4: Evaluate the Correct Expression
From the above analysis, the correct expression to find \( BC \) is:
\[ BC = 5 \cdot \tan 32^\circ \]