Im really bad at math so Im asking for help.
If the measures of three angles of a triangle are 8x-6,5x +10,and x +8,then the triangle is?
a)obtuse
b)right
c)acute
d)isosceles
explain...
2007-09-11 14:17:39 · 7 answers · asked by ryan9944 1 in Science & Mathematics ➔ Mathematics
Okay, all the angles in a triangle must add up to 180, so add all the angles and set them equal to 180. Then solve for x. Plug in x into all of the equations and if any angle is over 90 then it is obtuse, under 90 it is acute. or exactly 90 it is right. If two of the sides are the same length then it is isoceles.
so 8x-6+5x+10+x+8=180
group like terms
14x+12=180
14x=168
x=12
Then plug the answer back in to 8x-6, 8(12)-6= 90. Since one angle is 90 degrees, This is a right triangle!
2007-09-11 14:24:23 · answer #1 · answered by Erica 2 · 1⤊ 0⤋
the sum of the angles in a triangle = 180
8x - 6 + 5x + 10 + x +8 = 180
14x +12 = 180
14x = 180 -12
= 168
x = 168/14= 12
so the angles are 8x - 6 = 8(12) - 6 = 90 degrees
5x + 10 = 5(12) + 10 = 70 degrees
x + 8 = 12 + 8 = 20 degrees
so the triangle is right triangle since one of the angles is 90 degrees
2007-09-11 21:26:26 · answer #2 · answered by mohanrao d 7 · 1⤊ 0⤋
You know that the sum of the angles of a triangle equals 180 degrees. Therefore:
8x-6+5x+10+x+8 = 180 -->
14x+12 = 180 -->
14x= 180 - 12 -->
14x= 168 -->
x = 168/14 = 12
Now plug the above number in your angles. You have:
Angle 1 -----> 8x-6= 8*12-6 =90 degrees
Angle 2 -----> 5x+10=5*12 +10 =70 degrees
Angle 3 -----> x+8= 12 +8 = 20 degrees
The triangle is a right triangle, because one of its angles is 90 degrees.
Remember:
Obtuse triangle, is a triangle with one obtuse angle, i.e. a triangle with one angle between 90 and 180 degrees. This is not the case.
Acute triangle, is a triangle with three acute angles, i.e. a triangle with three angles less than 90 degrees. This is not the case, because one angle is actually equal to 90 degrees.
Finally, an isosceles triangle is a triangle with two equal angles. None of the angles are equal in our case.
Hope this helps :-)
2007-09-11 21:20:39 · answer #3 · answered by Anthony P - Greece 2 · 0⤊ 2⤋
The three angles in a triangle equal to 180.
8x-6 + (5x+10) + (x+8) = 180 solve for x
14x+12=180
14x=168
x=12
The angles are:
8x-6 = 8(12)-6= 90
5x+10=5(12)+10 = 60+10=70
x+8=12+8=20
An obtuse triangle means one angle is over 90 degrees.
A right triangle has one angle equal to 90 degrees.
An acute triangle means all the angles are less than 90 degrees.
An isosceles means two angles are the same.
In your case, one of the angles is equal to 90 degrees, so it is a right triangle.
2007-09-11 21:26:41 · answer #4 · answered by drewbear_99 5 · 0⤊ 0⤋
You know that the sum of all the angles of a triangle is 180. So add up those three expressions, set it equal to 180, and solve for x. Then use that x to find the exact values of 8x - 6, 5x+10, and x+8. If one of those values is 90, then you have a right triangle. If they're all less than 90, the triangle is acute, and so on.
2007-09-11 21:22:27 · answer #5 · answered by Anonymous · 0⤊ 1⤋
total of three anglesof a triangle=180
8x-6+5x+10+x+8=180
or,14x+12=180
or,14x=180-12
or,14x=168
or,x=12
So the angles are 90,70,20,
Therefore the triangle is a right angled triangle
2007-09-11 21:30:37 · answer #6 · answered by kamal 1 · 0⤊ 0⤋
D. Draw a 10 inch line. At the bottom end, horizontally, draw a 8 inch line. Connect the ends and see the triangle. There you go. I'm going out for coffee now.
2007-09-11 21:21:00 · answer #7 · answered by Mr. Wizard 7 · 0⤊ 1⤋