Math prob: using a protractor you must draw a triangle to find the third angle. If a=65 degrees, b=?, c=65 degrees and ac= 4 inches then b should equal 50 degrees, but I can't draw and come up with anything for b but 60. Anyone have a solution?
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Anonymous
ANSWERS: 8
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Yes it has to equal 50 degrees. Angles in a triangle add up to 180 degrees so 65+65=130 which leaves 50 How on earth can you get 60 with a protractor
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Usually I don't answer thee type of questions but this one is just a simple error on someone's part. The sum of the angles in every single triangle will always be 180! The angles of a triangle always add up to 180 degrees. An exterior angle of a triangle (an angle that is adjacent and supplementary to an internal angle) is always equal to the two angles of a triangle that it is not adjacent/supplementary to. Like all convex polygons, the exterior angles of a triangle add up to 360 degrees So with two angles being 65, the last angle MUST be 50 degrees. ALWAYS
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I don't understand, either. Maybe using protractor wrong?
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Not sure...prob is for my 5th grader. Haven't used one for 30 years.
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I admit I am not smarter than a 5th grader! Finally got it. Was multi-tasking with two kids and math...sometimes it is best to walk away and return later without mass confusion between 3rd grade and 5th grade math. Thank you for your help!
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Hmm... draw a horizontal line that's 4" long and mark the left A and the right C Place the protractor so that the centre (where the cross is) is on one end (A) and the 0 line is along the line and look around the protractor anticlockwise to 65. Draw a dot at this point. Draw a line from A to this point. Place the protractor so that the centre (where the cross is) is on the other end (C) and look around the protractor clockwise to 65. Draw a dot at this point. Draw a line from C to this point If the two lines cross mark the intersection B, if not extrapolate them until they do. This angle can be found by putting the 0 line on one of the lines and reading around to the other Sorry if that sounds patronising, no offence meant, but I am trying to explain it in simple terms
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The 4 inch length has no real relevance to the angles and is just so you have a length to draw one side, then add the two given angles to your drawing, extend the two given angles until they meet, forming point "b", then measure the last angle ... this is just an exercise in measuring to confirm that the sum of a triangle's angles is always 180° ... if you add the two given angles and then subtract their total from the constant value of 180°, then you can calculate the last angle without actually drawing and measuring ... ... the correct answer of course is ... b = 50° ...
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