So hmmm check the picture below
in an isosceles triangle, two sides are equal, and thus the angles those twin legs make, are also twin angles
let's say the angle made is "a", so all internal angles will be 64 + a + a = 180
or 64 + 2a = 180
thus 2a = 180 - 64 => 2a = 116, thus a = 116/2
in an isosceles triangle, two sides are equal, and thus the angles those twin legs make, are also twin angles
let's say the angle made is "a", so all internal angles will be 64 + a + a = 180
or 64 + 2a = 180
thus 2a = 180 - 64 => 2a = 116, thus a = 116/2