Ch. 10 Extra Credit ANSWER KEY to p.568 #1-15.  SHOW WORK for credit!!!

1.  x + x + 15 = 53                2.  1x + 3x + 8x = 180                                            3.  yes; rhombus
      2x  +   15 = 53                                12x   =  180
       2x           = 38                                    x    = 15
         x           = 19; 19 in.            So the angles are 15, 45, 120; obtuse triangle

SHOW YOUR WORK USING THE FORMULAS!
4.  A = 180 m²                     5.  A = 40 ft²                             6.  A = 72 m²

7.  diameter is 15 ft and so the radius is 7.5 ft
     A = 3.14(7.5)²                     C = 3.14(15)
     A = 177 ft²                           C = 47 ft.

8.  S = 2(3.14)(8)² + 3.14(16)(18)                9.  S = 3.14(12)² + 3.14(12)(15)            10.  S = 10² + 1/2 (40)(12)
     S = 1307 mm²                                               S = 1018 yd²                                            S = 340 ft²

11.  S = 2(1/2∙12∙5) + (5+12+13)(4)
       S = 180 cm²

12.  V = 4(4.5)(2.5)                    13.  V = 1/3(3.14)(7)² (15)                14.  V = 1/3(64)(6)
        V = 45 cm³                                 V = 770 in³                                        V = 128 ft³

15.  V = 3.14(2.5)² (3)
       V = 59 in³