Math Is Fun Forum

Daniel123

Member

Registered: 2007-05-23

Posts: 663

Trigonometry

I'm stuck with this...

Find x to 1dp

Thanks!

Last edited by Daniel123 (2007-07-19 00:52:15)

luca-deltodesco

Member

Registered: 2006-05-05

Posts: 1,470

Re: Trigonometry

well, with information there its unsolvable. unless the angle in top is meant to be a right angle or you've missed off another length or some other information?

Last edited by luca-deltodesco (2007-07-19 00:39:47)

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Daniel123

Member

Registered: 2007-05-23

Posts: 663

Re: Trigonometry

That's what I thought, but no other information is given - I have copied out the diagram exactly. It's in my summer work booklet preparing us for AS next year, so its not unlikely that the teachers would have made a mistake. It then asks to calculate the area of the triangle.. which obviously can't be done either, so I think I'll just leave it. Thanks though!

Last edited by Daniel123 (2007-07-19 01:10:57)

John E. Franklin

Member

Registered: 2005-08-29

Posts: 3,588

Re: Trigonometry

I examined the picture at the pixel level and determined
that it has a 45 degree angle where it says 53 degrees.
Hence, the screen ratio of the developer was 4:3, perhaps,
since the tangent of 53 degrees is close to 4/3.
And the triangle is isosceles, according to the pixels, so
the other angle is also 53 degrees, henceforth.
Do you think this is a joke?

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mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Trigonometry

Usually you're meant to assume that the diagrams aren't drawn particularly accurately, and use the information that you're given instead of measuring your own.

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JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Trigonometry

If the top angle is a right angle, x can be calculated straightaway without need for the “8cm” information.

You can tell that problem can’t be solved by constructing two possible triangles with the same given side and angle but different values of x. For example:

In the top diagram, x = 74; in the bottom one, x = 63.5.