acute angles of a right triangle are always complementary proof!!!!!?
965531
ALL triangles are ALWAYS 180 degrees.\nIf a triangle is "right", that means that one angle is 90 degrees.....meaning that the other two angles have to also equel to 90 degrees.....\nComplimentary means two angles equeling 90 degrees.....therefore, both of the acute angles are compimentary because they have no choice in the matter
744596
It helps to draw this out. Take the Sclene triangle ABC. AC is not equal to AC is not equal to CB.\nNow imagine we bisect an angle, say ABC with the line BD. \nNow if BD is perpedicular to AC, then ADB and CDB are both 90° and are equal. \nAnd clearly the line BD is equal to itself. And since we bisected the angle ABC then angle  ABD must be equal to angle CBD.\nThis means that triangle DAB and triangle DCB are conguent by Angle Side Angle.\nIf the triangles are congruent side AB must be equal to CB, and our original triangle must be isosceles.\n\nThis result contradicts our initial condition that the triangle is scalene, so the bisector of any angle is a scalene triangle cannot be perpendicular to the opposite side.\nQED
830426
The crux of this problem is for you to realize that the given angles are "complementary pairs", which add up to 90 degrees.\n\nYou are expected to know that the "co-function" of angle A gives the same value as the "function" of angle A's complement.\n\nSpecifically:\n\n cos(A) = sin(90-A)\n\nA graphical way of looking at this statement is that "cosine and sine are the same function, but offset by 90 degrees!"  We call that "out of phase by pi/2 or 90 degrees."\n\nThe same works for tangent and its co-function:\n\n tan(A) = cot(90-A)\n\nSo the answer to the second problem is 0.\n\nIf one of the fuctions in the first problem had been sin, the quotient would have been 1.  However, that's not the case, and I leave the upper problem as an exercise for another Answerer.\n\n Hope this helps!
661088
If the sides are parallel then these angles will be equal.
628550
same angle degree, same lenght of a side.
980380
There are several ways to prove two triangles are congruent (I believe this is what you are meaning by similar).\n\nProbably, several steps will need to take place before ultimately coming to one of three potentail final steps in a proof.\n\nThree final steps in proving the congruence of two triangles are:\n- ASA  (Angle Side Angle) - which means that the corresponding Angles, Side & Angles are equivalent\n- SSS (Side Side Side) - which means the three sides of the triangles are equivalent to the corresponding sides.\n- SAS (Side Angle Side) - which means the corresponding Sides and Angle of the two triangles are equivalent.\n\n*Note, there is no AAA theorem, as two triangles may have equivalent corresponding angles, but diff length sides.  These triangles would not be congruent.\n\nHere is an exerpt from a good site:\nHere is a quick summary of what each method of proof means:\n\n       SSS                SAS                ASA\n\n        +                    +                  +\n        /  &#92;                 /  &#92;                 /  &#92;\n     c/     &#92;a          c/     &#92;              /     &#92;\n     /        &#92;            /A     &#92;           /A   C &#92;\n   +-----------+   +-----------+  +-----------+\n          b                  b                  b\n\n        +                 +                +\n       /  &#92;               /  &#92;               /  &#92;\n    c/     &#92;a        c/    &#92;            /     &#92;\n     /       &#92;          /A    &#92;         /A  C &#92;\n    +------+    +--------+    +--------+\n          b                  b                  b\n\n    All three sides    Two sides and      Two angles and\n    of one triangle    the included       the included\n    agree with all     angle of one       side of one\n    three sides of     triangle agree     triangle agree\n    the other.         with the other.    with the other.
583757
Your statement is incorrect.  It reads:\n\n"In the image below, there are right angles. How would I prove that they're right angles without a protractor in any triangle?"\n\nActually, it should read:\n\n"In the image below, there are some angles."\n\nAnything else is pure conjecture.  (That means a guess.)\n\nIf you would like us to say something about those angles, you need to tell us how the figure was constructed.  After you tell us that, and ask your question more clearly, your answer will be obtained in short order.\n\nedit...\n\nYou have added some text in your extra text file that doesn't help at all:\n\n"I know that these green points are right angles..."\n\nSo you think a point can also be an angle.  It will be a long time before you get someone (who knows and understands geometry) to agree with that.\n\nIf you start over and explain what you want to know, in correct terms, you may have a chance at getting an answer.
563121
a right angled isosceles triangle\n\nplease give me 10 points now
718520
D.  The angles have to add up to 180.  If 2 of the angles are the same, then the 3rd has the same.  You have to get an enclosed side to be the same for the triangles to be congruent.
545927
A right angled triangle with short sides of 7cm and 11cm would have a long side (hypotenuse) of √(7²+11²)\nSo the square of the length of the longest side would be \n49 + 121 = 170 \n16² = 256, so this side is too long to make a right-angled triangle - the two short sides would have to open up a bit - making an angle greater than 90°...\n\nI have heard of a right angled triangle, but acute and obtuse are used to describe angles, in my experience...\nAs the internal angles in a triangle sum to 180°, clearly if one angle is obtuse or 90°, the other two must be acute.\nThe question may be referring to one specific angle in the triangle - so the answer is here, anyway!
797707
See the picture:\n\nhttp://mudandmuck.com/str2/sin&cos.jpg\n\nThe two triangles in the picture are equivalent.  (Same angles, and one side of each we know to be the same (hypotenuse=1), so all the sides have the same absolute length, only their signs are different.)
356323
Absurd... A triangle cannot have more than 1 obtuse angle, since the sum of all angles of a triangle is 180 degrees.
724499
It is a tough Q - coz it is NOT right angle...\nThe best solution would be to name the angles, LHS Triangle as angle x, y z,,,,,     RHS triangle as  x', y', z'\n\nThe actual proof will be long, but the basic idea is\nSum of the Angles of a Tri = 180\nand the angles in straight line = 180\n\nx + y + z =180\n\nx' + y' + z' = 180\n\nz + y' = 180\n\ny' = 180-z                                                 \n\nx = x'\n\nx' + 180-z + z' = 180\nx + z' = z\n\nTherefore, z is larger Angle than x  (or x')\n\nSide opposite to larger angle is larger
151270
Then none of the angles are congruent either. :) It's just a right triangle.....
1063947
well, right angles will always be similar, bcuz they r all 90 degrees. however, many triangles r different. try measuring their corners w/ a protracter 2 find out if they r alike.
442290
1. pythagoros theorem applies to any right angled triangle.\n\n2. The geometric mean of a set of positive data is defined as the nth root of the product of all the members of the set, where n is the number of members.\n\n3. in an isosceles triangle 2 sides and 2 angles are equal\n\n4.hypotenuse is opp. to the right angle.it is the largest side.\n\n5.true
749245
For indirect proofs you start with the opposite of the conclusion.\nIn this case, you take the opposite of "the angles opposite those sides are not congruent" and make it "the angles opposite those sides are congruent".  Therefore, two sides of a triangle are congruent since if the base angles are congruent, the sides are congruent.  Then you state it's a contradiction because it contradicts the given fact that the two sides of a triangle are not congruent.  Then you just say therefore, our assumption is incorrect and the angles opposite those sides are not congruent.