How do you find the measures of an incoselces triangle that has the measures of:
3x-11
and
2x+11
(which are the base angles)
and the vertex angle is 2y
2006-11-28 11:29:40 · 6 answers · asked by Anonymous in Education & Reference ➔ Homework Help
Cool geometry im learning this in class 2bad i cant help u cuz im faling -.-
2006-11-28 11:31:57 · answer #1 · answered by sonya3091 3 · 0⤊ 0⤋
I assume you are talking about the measure of the angles. Assuming you are working in degrees:
Given that an Isosceles triangle has at least two equal angles and that your base angles are 3x - 11 and 2x + 11
3x - 11 = 2x + 11 or
x - 11 = 11 or
x = 22
That would mean that the base angles are 55 degrees.
Since the sum of the angles of any triangle equal 180 degrees, then the remaining angle is 70 degrees. From this we get the following equation given that the stated size of the remaining angle is 2y:
2y = 70
y = 35
2006-11-28 11:47:45 · answer #2 · answered by Magic One 6 · 0⤊ 0⤋
It's easy.
If I am understanding this properly then base angles means the angles that are isosceles:
3x -11 = 2x + 11
x = 22
[3x -11 ] + [2x+11] + 2y = 180
as x=22
[66-11] + [44 +11] + 2y =180
2y = 180 - 55 -55
= 70
y = 35.
There.
2006-11-28 11:38:39 · answer #3 · answered by Vernita G 2 · 0⤊ 0⤋
Okay... in an isosceles triangle, you know that two of three sides are equal, so the base angles are equal.
Therefore base angle 1 = base angle 2
3x-11=2x+11
3x-2x=11+11
x=22
so base 1 3(22) - 11 = 55 degrees
base 2 2(22) + 11 = 55 degrees (see? told you they were equal - lol)
The sum of all three angles total 180 degrees... so now that you know two of the angles, just subtract them from 180 to get 70.... or the long way...
55 + 55 + 2y = 180
110 + 2y = 180
2y = 180-110
2y= 70
y=35
so the vertex angle measures 2(35) = 70
2006-11-28 11:49:41 · answer #4 · answered by LaLa 6 · 0⤊ 0⤋
You set the two equal angles equal to each other and solve: 3x-11 = 2x+11 will be the equation. Once you find x plug it in to get the angles.(x should come out to be 22)
To find the final angle use following equation:
180 - [ (2x+11) + (3x-11) ] = 2y
2006-11-28 11:44:35 · answer #5 · answered by Jay 1 · 0⤊ 0⤋
Didn't you ever learn the postulate: If the sides are congruent, than the angles are congruent? Well, because it's an isoc triangle, the 2 sides are congruent. Just do 3x-11=2x+11. That'll get you started. I'm not telling you anymore, because i'm sure you have a text book . . . .
2006-11-28 11:42:25 · answer #6 · answered by Anonymous · 0⤊ 0⤋