What is the angle needed to solve this right triangle?

In summary: The problem is that the angles given do not make sense. In order to have a right angle at ##A##, the sum of the other two angles must be ##90^\circ##, which is not the case here. So it is most likely a typo and you can use the hint given to find the correct angle. In summary, the given problem involves finding the length of sides AB and CD in a right triangle with angles 41.45 and 32.73 degrees. However, upon checking the answer in the textbook, it was found to be incorrect. After trying a different angle, it was discovered that there was a typo in the problem. The correct angle needed to solve the problem was missing, but a hint was given
  • #1
nmnna
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3
Homework Statement
In figure ##\angle{ABC} = 90^\circ = \angle{BCD}, \ \angle{ACB} = 41.45^\circ, \ \angle{CBD} = 32.73^\circ, \ BC = 10##cm. Calculate ##AB, \ CD## and ##\angle{AEB}##
Relevant Equations
##\tan{\alpha} = \frac{opposite \ side}{adjacent \ side}##
The Figure
1616228240588.png

My Attempt at Solution

##\tan{ACB} = \frac{AB}{BC}, \ \tan41.45^\circ = \frac{AB}{10} \Rightarrow AB = 10\tan45.41^\circ \approx 8.83##cm
Similarly
##\tan{CBD} = \frac{CD}{BC}, \ \tan32.73^\circ = \frac{CD}{10} \Rightarrow CD = 10\tan32.73^\circ \approx 6.43##cm
After this I checked the answer in my textbook, and instead of 6.43cm the answer for ##CD## was 4.40cm.
I thought that there was a typo in the problem, so instead of ##32.73^\circ##, I tried ##23.73^\circ##, and surprisingly the answer matches with the one in the textbook.
So I'd like to know if it really is a typo or my solution is wrong.
And I can't find the angle required in the problem, so I'd be grateful if you give me some hints for finding this angle.
 
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  • #2
nmnna said:
Homework Statement:: In figure ##\angle{ABC} = 90^\circ = \angle{BCD}, \ \angle{BCD} = 41.45^\circ,
You have angle ##BCD## twice there. Please clarify.
 
  • #3
PeroK said:
You have angle ##BCD## twice there. Please clarify.
It should be ##ACB##
 
  • #4
nmnna said:
So I'd like to know if it really is a typo or my solution is wrong.
And I can't find the angle required in the problem, so I'd be grateful if you give me some hints for finding this angle.
Looks like a typo.

A hint to find the angle ##AEB##. First extend the line ##AB## to a new point, ##F##, so that ##AFD## is a right angle. Then you have another angle equal to ##AEB##.
 
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  • #5
Your work is correct starting with the numbers you were given.
 
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FAQ: What is the angle needed to solve this right triangle?

What is a right triangle?

A right triangle is a type of triangle that has one angle measuring 90 degrees. This angle is known as the right angle, and it is formed by the intersection of the two sides of the triangle that are perpendicular to each other.

How do you solve a right triangle?

To solve a right triangle, you need to know at least two of its side lengths or angles. You can then use trigonometric ratios (sine, cosine, and tangent) to find the missing sides or angles. Alternatively, you can use the Pythagorean theorem if you know the lengths of two sides.

What are the trigonometric ratios?

The trigonometric ratios are sine, cosine, and tangent, and they relate the angles of a right triangle to its side lengths. Sine is the ratio of the opposite side to the hypotenuse, cosine is the ratio of the adjacent side to the hypotenuse, and tangent is the ratio of the opposite side to the adjacent side.

How do you use the Pythagorean theorem to solve a right triangle?

The Pythagorean theorem states that in a right triangle, the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides. To use this theorem, you need to know the lengths of two sides of the triangle, and you can then solve for the third side using simple algebraic equations.

What are some real-life applications of solving right triangles?

Solving right triangles is used in various fields such as architecture, engineering, navigation, and astronomy. It is used to calculate distances, heights, and angles in real-life scenarios. For example, architects use right triangle trigonometry to determine the slope of a roof, and engineers use it to calculate the height of a building or the angle of a bridge.

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