20 APPLIED SCIENCE 



Area of triangle = base X one-half altitude 



Area of parallelogram = base X altitude 



Area of trapezoid = altitude X one-half the sum of parallel sides 



Questions 



1. What measuring instrument is used to measure the length 

 of a 9-ft. plate? 36-ft. boat? 20-ft. wind-shield? 



2. What measuring instrument is used to measure the width 

 of lumber? Length of bolts? Screws? 



3. What measuring instrument is used to measure the diameter 

 of a cylindrical metal bar? Balls? 



4. What measuring instrument is used to measure the inside 

 diameter of pipes? Elbows? 



5. What measuring device is used in measuring the length and 

 width of a table? 



6. A foreman desires to measure the length of the shop floor. 

 What measuring tool should he use? 



7. What objection may be raised to measuring the length of a 

 school room with a 2-ft. rule? 



8. An apprentice was told to obtain the diameter of a pulley 

 by measuring the longest distance across the pulley. Was this 

 instruction correct? 



9. How may the diameter of a small iron ball be obtained 

 accurately? 



10. Is there an exact number that shows the exact relation 

 between the meter and the foot? 



11. Give the advantages and disadvantages of the metric system 

 of weights and measures. English system. 



12. Explain some of the reasons why the metric system has 

 not been extensively adopted in this country. 



Problems 



1. What is the area of a square surface 14 in. on a side? Give 

 the area in square feet. 



2. What is the area of a rectangular surface 1 ft. 5 in. by 8 in.? 

 Give the area in square feet. 



3. What is the area of circular piece of metal with a diameter of 

 8 in.? 



