The problem asks us to find the values of $x$ and $y$ in two right triangles using trigonometric ratios. In the first triangle, the hypotenuse is 12cm, and one angle is 45 degrees. We need to find $x$ (opposite) and $y$ (adjacent). In the second triangle, the hypotenuse is 6km, one angle is 30 degrees, and we need to find $x$ (opposite) and $y$ (adjacent). Then, we're asked to use the values found to calculate another value of $y$ given $x = 3km$ and an angle of $30^\circ$.

GeometryTrigonometryRight TrianglesSineCosineTangentAngle Relationships
2025/3/11

1. Problem Description

The problem asks us to find the values of xx and yy in two right triangles using trigonometric ratios. In the first triangle, the hypotenuse is 12cm, and one angle is 45 degrees. We need to find xx (opposite) and yy (adjacent). In the second triangle, the hypotenuse is 6km, one angle is 30 degrees, and we need to find xx (opposite) and yy (adjacent). Then, we're asked to use the values found to calculate another value of yy given x=3kmx = 3km and an angle of 3030^\circ.

2. Solution Steps

For the first triangle:
(i) To find yy (adjacent), we can use the cosine function:
cos(θ)=adjacenthypotenusecos(\theta) = \frac{adjacent}{hypotenuse}
cos(45)=y12cos(45^\circ) = \frac{y}{12}
y=12cos(45)y = 12 \cdot cos(45^\circ)
y=1222=62y = 12 \cdot \frac{\sqrt{2}}{2} = 6\sqrt{2}
y8.485cmy \approx 8.485 cm
(ii) To find xx (opposite), we can use the sine function:
sin(θ)=oppositehypotenusesin(\theta) = \frac{opposite}{hypotenuse}
sin(45)=x12sin(45^\circ) = \frac{x}{12}
x=12sin(45)x = 12 \cdot sin(45^\circ)
x=1222=62x = 12 \cdot \frac{\sqrt{2}}{2} = 6\sqrt{2}
x8.485cmx \approx 8.485 cm
For the second triangle:
(i) To find xx (opposite), we can use the sine function:
sin(θ)=oppositehypotenusesin(\theta) = \frac{opposite}{hypotenuse}
sin(30)=x6sin(30^\circ) = \frac{x}{6}
x=6sin(30)x = 6 \cdot sin(30^\circ)
x=612=3kmx = 6 \cdot \frac{1}{2} = 3 km
(ii) The final part involves using the tangent function and the previously calculated value of x=3kmx=3km and the given angle of 3030^\circ to find yy:
tan(θ)=oppositeadjacenttan(\theta) = \frac{opposite}{adjacent}
tan(30)=3ytan(30^\circ) = \frac{3}{y}
y=3tan(30)y = \frac{3}{tan(30^\circ)}
y=313=33y = \frac{3}{\frac{1}{\sqrt{3}}} = 3\sqrt{3}
y5.196kmy \approx 5.196 km

3. Final Answer

y8.485cmy \approx 8.485 cm
x8.485cmx \approx 8.485 cm
x=3kmx = 3 km
y5.196kmy \approx 5.196 km

Related problems in "Geometry"

We need to describe the domain of the following two functions geometrically: 27. $f(x, y, z) = \sqrt...

3D GeometryDomainSphereHyperboloidMultivariable Calculus
2025/6/3

We need to find the gradient of the line passing through the points $P(2, -3)$ and $Q(5, 3)$.

Coordinate GeometryGradientSlope of a Line
2025/6/3

The problem presents a diagram with a circle and some angles. Given that $\angle PMQ = 34^\circ$ and...

Circle GeometryAnglesCyclic QuadrilateralsInscribed Angles
2025/6/3

In the given diagram, we are given that $∠PMQ = 34°$ and $∠NQM = 28°$. We need to find the measure o...

AnglesCirclesCyclic QuadrilateralsTriangles
2025/6/3

We need to sketch the graph of $f(x, y)$ for the following functions: 7. $f(x, y) = 6$ 8. $f(x, y) =...

3D GeometrySurfacesPlanesCylindersParaboloidsEllipsoidsHemispheres
2025/6/3

The problem provides the measures of the six interior angles of a hexagon in terms of $x$. The task ...

PolygonHexagonInterior AnglesAngle SumAlgebra
2025/6/3

We are asked to describe the graphs of several functions of two variables, $f(x, y)$.

3D GeometryFunctions of Two VariablesPlanesCylindersSpheresEllipsoidsParaboloids
2025/6/3

We are given that a sector of a circle has a radius of 21 cm and subtends an angle of $120^{\circ}$ ...

Arc LengthCirclesSectorTrigonometry
2025/6/3

Problem 30: We are given a right triangle $PQR$ with $\angle PQR = 90^\circ$, $|QR| = 2$ cm, and $\a...

TrigonometryRight TrianglesTriangle Angle SumAngle Ratios
2025/6/3

Question 28: The probability that a seed planted will germinate is 0.75. If 3 of such seeds are plan...

ConeVolumeRadius
2025/6/3