I've forgotten my geometry from high school. Is there a relativley simple way to determine the angle of a blade? I mean, the angle to which a blade is ground, from spine to edge? (I'm not asking about sharpened edge angles, but the whole blade.) For instance, my full size Manix ... at thickest part of spine, about 4mm. Depth of blade, about 34mm. Another way to ask the question: How does one calculate the most acute angle (vertex) on an isosceles triangle?