In a right triangle with acute angle θ, the side adjacent to θ has length 3 and the hypotenuse has length 9. Find the length of the side opposite of θ.
Question
In a right triangle with acute angle θ, the side adjacent to θ has length 3 and the hypotenuse has length 9. Find the length of the side opposite of θ.
Solution
In a right triangle, the relationship between the sides is given by the Pythagorean theorem, which states that the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides. However, in this case, we can use the trigonometric function sine to find the length of the side opposite of θ.
The sine of an angle in a right triangle is defined as the ratio of the length of the side opposite the angle to the length of the hypotenuse. So, we have:
sin(θ) = opposite/hypotenuse
We know that the length of the side adjacent to θ is 3 and the length of the hypotenuse is 9. We can use the cosine function to find the sine of θ, because cosine of an angle in a right triangle is defined as the ratio of the length of the side adjacent to the angle to the length of the hypotenuse. So, we have:
cos(θ) = adjacent/hypotenuse = 3/9 = 1/3
Since sine and cosine are related through the identity sin^2(θ) + cos^2(θ) = 1, we can find sin(θ) as follows:
sin(θ) = sqrt[1 - cos^2(θ)] = sqrt[1 - (1/3)^2] = sqrt[1 - 1/9] = sqrt[8/9] = 2sqrt(2)/3
Finally, we can find the length of the side opposite of θ by multiplying the sine of θ by the length of the hypotenuse:
opposite = sin(θ) * hypotenuse = (2sqrt(2)/3) * 9 = 6sqrt(2)
So, the length of the side opposite of θ is 6sqrt(2).
Similar Questions
Given a right triangle, solve for θ.
To find the size of the angle \(\theta\) in the right-angled triangle, we can use trigonometric ratios. Given that we have the length of the adjacent side (6) and the hypotenuse (8), we can use the cosine function: \[ \cos(\theta) = \frac{\text{adjacent}}{\text{hypotenuse}} = \frac{6}{8} = \frac{3}{4} \] Now, we need to find the angle \(\theta\) whose cosine is \(\frac{3}{4}\). We can use the inverse cosine function (also known as arccos): \[ \theta = \cos^{-1}\left(\frac{3}{4}\right) \] Using a calculator to find the inverse cosine: \[ \theta \approx \cos^{-1}(0.75) \approx 41.4^\circ\] Therefore, the size of the angle \(\theta\) to one decimal place is: \[ \boxed{41.4^\circ} \]
To find the size of the angle \(\theta\) in the triangle with sides of lengths 3, 6, and 8, we can use the Law of Cosines. The Law of Cosines states: \[ c^2 = a^2 + b^2 - 2ab \cos(\theta) \] In this case, \(a = 3\), \(b = 8\), and \(c = 6\). We need to find the angle \(\theta\) opposite the side of length 6. 1. Substitute the given values into the Law of Cosines: \[ 6^2 = 3^2 + 8^2 - 2 \cdot 3 \cdot 8 \cdot \cos(\theta) \] 2. Simplify the equation: \[ 36 = 9 + 64 - 48 \cos(\theta) \] 3. Combine like terms: \[ 36 = 73 - 48 \cos(\theta) \] 4. Isolate \(\cos(\theta)\): \[ 36 - 73 = -48 \cos(\theta) \] \[ -37 = -48 \cos(\theta) \] \[ \cos(\theta) = \frac{37}{48} \] 5. Use the inverse cosine function to find \(\theta\): \[ \theta = \cos^{-1}\left(\frac{37}{48}\right) \] Using a calculator to find the inverse cosine: \[ \theta \approx \cos^{-1}\left(\frac{37}{48}\right) \approx 40^\circ \] Therefore, the size of the angle \(\theta\) to the nearest degree is: \[ \boxed{40^\circ} \]
If sec θ = √2 and cot θ < 0, then find the exact value of cot θ.*−(√2)√2−11In ∆ABC, ∠A is a right angle and m∠B=45. How long is side BC if AB+AC=16?*8√2 units4√2 units16√2 units2√2 unitsIn a right triangle with acute angle θ, the side adjacent to θ has length 3 and the hypotenuse has length 9. Find the value of csc θ.*(3/4)√2(2√2)/331/3
The Pythagorean Theorem states that for a right-angled triangle 4ABC, as in figure, a2 =b2 + c2. Use this equation to prove that sin2 θ + cos2 θ = 1
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.