RULES FOR AREA AND VOLUME OF DIFFERENT 

 FIGURES 



Area of Square. Multiply the length of side by itself, 

 or, as is said, " square " it. 



Area of Rectangle. Multiply the base by the altitude. 



FIGURE A 



Area of Parallelogram. (Figure A.) Multiply base a b 

 by altitude b c, not by b d. If b d and the angle at d are 

 known, b c may be found by the formula 



be = bd X sine of angle at d. 



Area of Triangle. (Figure B.) Multiply base a b by 

 altitude c d and divide by 2. 



Area of Triangle with 3 Sides Given. (Figure B.) Add 

 the 3 sides together and divide the sum by 2. From this 

 half sum take each side in succession. Multiply the half 

 sum and the remainders all together and take the square 

 root. The formula is 



V|(i*-a)(i-6)(J* c) 



Circle. Circumference equals diameter X 3.1416. 

 Area of Circle. (Figure C.) Square the diameter, 

 multiply by 3.1416, and divide by 4. 



