In what respect do they differ? What particular name may be given to Fig. C? What one to Fig. D? What three names may you give to the figure with right angles? What three to the one _without_ right angles? RHOMBOID AND RHOMBUS. In what three things are Figs. E and F alike? What three names may be given to each? How do they differ from each other? What particular name may you give to Fig. F? What four names has Fig. F? RECTANGLE AND SQUARE. In what three things are Figs. G and H alike? On account of the number of their sides, what may each be called? Because their opposite sides are parallel, what may each be called? Because they have right angles, what may they be called? In what respect is Fig. H different from Fig. G? On this account, what particular name may be applied to Fig. H? What three names may be applied to Fig. G? What _four_ to Fig. H? RHOMBUS AND SQUARE. In what three things are Figs. F and H alike? On account of the number of their sides, what name may be given to each? Because their opposite sides are parallel, what name may be given to each? Because both are parallelograms, and both have their sides equal, what name may be given to each? What particular name has Fig. F? What particular name has Fig. H? What four names may be given to Fig. F? What four to Fig. H? LESSON TWENTY-NINTH. REVIEW. What two names may be given to Fig. A. (DIAGRAM 22.) To Fig. B? In what are they alike? In what do they differ? By what three names may Fig. C be called? By what three names may Fig. D be called? In what two things are they alike? In what one thing do they differ? What particular name has C? What one has D? What three names may be applied to Fig. E? What four to Fig. F? What property has F that E has not? What particular name has it on that account? What three names has Fig. G? What four has Fig. H? What property has Fig. H that G has not? What particular name has it in consequence? What four names may you give to Fig. F? What four to Fig. H? What three names may be applied to either? In what three things are they alike? In what respect do they differ? What particular name has Fig. F? What particular name has Fig. H? [Illustration: Diagram 23.] LESSON THIRTIETH. MEASUREMENT OF SURFACES. In Fig. 1 (DIAGRAM 23.) call the line _a b a_ unit. Rectangle 1 is how many units long? How many high? Because its sides are equal, what is it called? Rectangle 2 is how many units long? How many high or wide? How many squares does it contain? Rectangle 3 is how many units long? How many wide? How many squares does it contain?