Isocoleese means that 2 sides are the same legnth that also means that 2 angles are the same legnth so represent the angles as x,y,z the vertex is the different angle lets says that x=y because they are the 2 same angle and z=vertex so just do the angles measure x,x,z because x=y so base angle=x=y remember that all 3 inside angles added together equals 180 so x+y+z=180 or x+x+z=180 so we have
measure of each of the base angles of the isosolese triangle is 9 les than 4 times the vertex that means that x is 9 less than 4 times z or x=-9+4z or x=4z-9 so we have the other equation x+x+z=180 subsitute 4z-9 for x 4z-9+4z-9+z=180 group like terms 4z+4z+z-9-9=180 add like terms 9z-18=180 add 18 to both sides 9z=198 divide both sides by 9 z=22 subsitute x=4z-9 x=4(22)-9 x=88-9 x=79
x=y=79
the angles are base angles=79 degrees vertex=22 degrees
