math
posted by derek on .
if the measures of the angles of a triangle are represented by 2x, 3x15, and 7x15, the triangle is
1)an isosceles triangle
2)a right triangle
3)an acute triangle
4)an equiangular triangle

The sides are different lengths so it is not isosceles or equiangular
(2x)^2 = 4x^2
(3x15)^2 = 9x^2 60x + 225
(7x15)^2 = 49x^2  etc
so a^2 +b^2 is NOT equal to c^2 so it is not a right triangle
Now lets see what x is:
2x + 3x +7x 30 = 180
12 x = 210
x = 17.5
so the three angles are:
2x = 35
3x15 = 37.5
7x15 = 107.5
so I would pick 3) 
Add up the angles and set the sum equal to 180 (degrees). Then solve for x. Then see what the actual angles are and decide what kind of triangle it is.
Is "none of the above" an option? 
hmm, now that you mention it, I would not pick any :)