2007-12-06 06:38:45 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
You need to know at least one angle as well. Then you can apply the Law of Cosines, which relates the side c opposite the angle C to the other two sides:
c² = a² + b² - 2abcosC
Solve for the missing side.
If the angle C = 90° the formula simplifies to the the Theorem of Pythagoras.
2007-12-06 06:53:56 · answer #1 · answered by Helmut 7 · 1⤊ 0⤋
If it is a 'right angled' triangle then use Pythagoras theorem.
h^2 = a^2 + b^2
If it is an Isosceles Triangle - 2 sides the same length,- then drop a bisecting perpendicular from the angle between the two equal sides to the non-equal side. This will bisect the base. Then use use trigonometry functions to find the third side. For this method your will need to know the numerical size of one of the angles.
If it is a scalene( all sides of different length & no right angle) triangle then use either the Cosine Rule or the Sine Rule.
Again you will need to know the value of one of the angles.
Cosine Rule:
a^2 = b^2 + c^2 - 2bcCosA
Where small case letters are the length of the sides and the large case letter is the angle opposite to the corresponding lettered side.
Sine Rule;
a/SinA = b/SinB = c/SinC
Where small case letters are the length of the sides and the large case letter is the angle opposite to the corresponding lettered side.
Hope this helps!!!!
2007-12-06 06:53:44 · answer #2 · answered by lenpol7 7 · 1⤊ 2⤋
If it is a right triangle, you can use the pyythagorean theorem. Otherwise, I'd need the lengths, and would drop an altitude to the unknown side and go from there.
2007-12-06 06:45:48 · answer #3 · answered by mom 7 · 1⤊ 1⤋
If the 2 sides you have are the same, then make that the same length as the others.
2007-12-06 06:41:55 · answer #4 · answered by Yahoo man 2 · 0⤊ 3⤋
a^2 + b^2 =c^2
2007-12-06 06:41:30 · answer #5 · answered by Here and There 3 · 0⤊ 3⤋
I believe you need to know one of the angles at least to find the other side.
2007-12-06 06:49:26 · answer #6 · answered by FunnyGuy 2 · 3⤊ 0⤋
If it is a right angled triangle u can use pythagoras therum and if it isn't one you can construct one with pencil and then measure the last side with a ruler.
2007-12-06 06:51:50 · answer #7 · answered by rashid m 1 · 0⤊ 1⤋
You don't have enough information to solve this problem. You need at least the size of 1 angle. If that
information is available, re-post your question with
that information included. Otherwise, no way to solve.
2007-12-06 06:49:17 · answer #8 · answered by Grampedo 7 · 3⤊ 0⤋
do you know the longest side?
Do you know the angle the two sides you have make with one another....
knowing this, you can use the law of cosines ....
a^2 + b^2 -2ab cos(Angle)= c^2
c^2 -b^2 + 2cb cos(angle)= a^2
2007-12-06 07:00:11 · answer #9 · answered by Brian D 5 · 1⤊ 1⤋