From the same point draw two straight lines of any length, making an acute angle with each other.
Make them equal to each other by measuring.
Join their ends.
What kind of a triangle is it on account of its angles?
On account of its two equal sides?
Write its two names inside of it.
Draw an isosceles triangle whose equal sides shall each be less than the third side.
Write its two names within it.
Draw an oblique straight line twice as long as any short measure or unit.
At one end draw a straight line perpendicular to it, and three times as long as the same measure.