How do I break up an obtuse triangle into a number of acute triangles?
611646
Simply bisect the obtuse triangle once and only once through point at which the A side and B side intersect through the middle of C. \n\nSince a triangle, by defintion, has 3 angles that equal 180 degrees, the smallest angles would be, using whole numbers for clarity, 178deg, 1deg and 1 deg. Bisecting the 178deg angle makes two 89deg angles, which is under the definition of an acute angle. \n\nSince an acute angle is defined as an angle less than 90deg, and a triangle is defined as having 3 angles with a sum of 180deg, we know that the 180deg can not be just one angle (180deg, when bisected, creates 2 right angles) and still be a triangle. Therefore, we know that for any triangle ABC with an obtuse angle at AB, bisecting the angle once, and only once, through AB to the midpoint of C will create two right triangles with angles of 90deg, 90deg - angle#1deg, and 90deg - angle#2deg.
288646
Your question is a little bit generic. You can draw a lot of "angles and triangles" with a compass.\nThe simplest procedure that comes to my mind is this:\n1) Trace an horizontal segment from a point A to another point B.\n2) Now point your compass in A, with radius equal to AB and trace an arc over the segment.\n3) Then point in B with the same radius and trace another arc. The two arcs will intersect in a third point C.\n4) If now you join A with C and C with B, you have a triangle with all segments and angles equal.\nBe more specific if you need more help.
278653
15: First you cut the triangle in half so the hypotenuse is 17 and the bottom leg is 8 (half of 16=8) and then use Pythagorean theorem so it would be 17^2 - 8^2 (=225) and take the square root of that (=15).\nGood luck on your midterm!
87753
Just add up the lengths of the three sides. Works for any triangle - wether it's equilateral, isosceles or obtuse.
322891
The obvious way is by trisecting each of the triangle's 60 degree angles and projecting the lines to the circle's circumference.\n\nBut trisecting an angle is impossible with simple geometric tools.  \n\nSee this for an interesting discussion:  http://www.jimloy.com/geometry/trisect.htm\n\n\n\nn.b.  a compass is a magnetic navigational instrument.\n\nThe drawing instrument used for scribing arcs and circles is a pair of compasses.
841334
Easiest way would be to drop a bisector from two of the angles.  The intersection will be the centroid.  This is assuming a regular pentagon.\n\nIf it is an irregular pentagon, you could tie a weight to a string.  Hold the pentagon by a vertex while also holding the string.  This line passes through the center of gravity.  Do the same for another vertex.  The lines will intersect at the centroid (aka center of gravity).  This method would work for a regular pentagon also since the lines would be the angle bisectors.
38263
5.196 (3 times root 3)\nDive the triangle into 3 equal triangles.  Then divide each one of those triangles into 2 triangles.  The hypotnuse of each triangle has a length of 2, and by trig. (it is a 30-60-90 triangle) the base has a length of the square root of 3 and the height is 1. Area of a triangle =(base times height)/2=(radical 3)/2.  There are 6 smaller triangles total, so multiply the area by 6=total area=3 times radical 3 (5.196)\nHope this helps, it would be a lot easier if I had a picture that I could post and it would make more sense.
777719
Mark you first two corners 20 m apart.\nThe third marker must be 20 m away from one corner and the other must be 20*sqrt(2) = 28.284 meters from the other corner (The length of the diagonal of a square is sqrt(2) * the side, so that distance will ensure that you have right angles.)\n\nSo tie a length of rope (no stretch), to each of the first two markers.  Cut the ends at 20m and 28.284 m respectively.  Hold the two ends together and find the spot where both ropes are taut.  That's where your third marker goes.\n\nAgain, your last marker should be 28.284m from its opposite.
99265
I asked that same question to my teacher last time. She told me that I have to Seperated the shape into different common shapes. (for example like lets say I wanted to seperate a "square" into some common shapes I could turn it into two seperate triangles or four different triangles. Well Just try to use the formulas you know for the areas of the different disected figures you get.
534524
A nonagon can be broken into 9 isoceles triangles.\nThe vertex angles will be 360/9 = 40 degrees.\nThe two sides adjacent to the vertex have length 1 meter\nEach of the 9 triangles can be split into 2 right triangels with angles of 20 and 70 degrees.\nThe side opposite the 20 degree angle is sin(20) meters.\nThe side adjacent the 20 degree angle is cos(20) meters.\n\nEach of those triangles will have area (1/2)sin(20)cos(20 m^2\n\nThe total area of the 18 triagles combined is 9sin(20)cos(20).
953741
Just break the pentagon up into 5 triangles.  You can then add together the area of the 5 triangles to get the total area.
400701
what you want to do is draw an isosoles triangle with the 2 congruent angles the size you want. \n\nStart with a base with a certain length (use the compas to measure, say 4 inches).  Next determine the midpoint by marking arcs nboth above and below your line from each endpoint using the same compass diameter, then drawing a line through the two intersections.  You now have a right abngle at the midpoint.  You can now determine how tall your triangle must be using the sin table and use your compass to mark the point on the vertical line to complete the triangle with the angle you want.
717001
Since the triangle is Isoceles, if you split the triangle down the middle you can turn in into a right triangle. You can use the Pythagorean theorem. (a^2 + b^2 = c^2.)\n\n13 will be the hypotenuse and 5 will be the base. To find the altitude you just fill everything in. \n\n5^2 + b^2= 13^2\n25 + b^2 = 169\nb^2 = 144\nb = 12
356323
Absurd... A triangle cannot have more than 1 obtuse angle, since the sum of all angles of a triangle is 180 degrees.
563121
a right angled isosceles triangle\n\nplease give me 10 points now
506764
well, id need a pic to explain it...but, you can draw two lines from the midpoint of one of the sides, and then you have 4 triangles...the big one, and three little ones inside...
544028
You have to have a right triangle.\nThen you figure out which is side is opposite or adjacent from the angle you need.