Idiot\'s Guides Basic Math and Pre-Algebra

Extra Practice Answers 331

71. If m’J = 80r, m’M 80 r, then m’A =
    180 – (80r + 80r) = 20r.


72. If AR = 7 cm, RM = 13 cm, and 'ARM is
    isosceles, then AM = 7 cm or 13 cm.


73. LG must be at least 13 cm but not more
    than 21 cm.


74. 'MAT cannot be a right triangle because
    42 + 4^2 { 62.


75. 'COW is a right triangle with right angle
    ’O. If CW = 65 cm and CO = 25 cm, then
    OW = 6522  25 3,600 60 cm.


76. If 'PAT # 'POT and m’A = 70r, then
    m’O = 70r


77. 'DOG # 'CAT, and DO = 28 inches,
    OG = 34 inches, and DG = 45 inches,
    CT = DG = 45 inches


78. PG = 27 cm


79. RU = 28 cm


80. m’PAY = m’L + m’P, so 115r = 75r +
    m’P, and m’P = 40r

14

21

18

14 378

27

x

x

x

   x x x x x

814

10

14 x 10 x 80

480

20

828 







 



81. ACFH is a quadrilateral with AC FH,
    AH CF and CA HA. ACFH is a rectangle.


82. BJ = JK = KD = DB. BDKJ is a rhombus.


83. JK GI and JI KG. JKGI is a
    parallelogram.


84. In rhombus BDJK, BD = 12 cm.
    In parallelogram JKGI, GI = 12 cm.


85. A = bh = 12 v 5 = 60 square inches


86. If m’A = 58r, m’B = 180 – 58 = 122r.


87. If BC = 29 cm and AD = 41 cm,
    MN =^12 (29 + 41) =^12 (70) = 35 cm.


88. If PQ RS, the trapezoid is isosceles.
    If m’Q = 119r, m’S = m’P = 180 – 119
    = 61r.


89. A =^12 (24 + 18) v 15 =^12 (42) v 15 =
    21 v 15 = 315 cm^2


90. The median =
    1
    2
    b 1 b 2 = 15.
    A^1 b 1 b 2 h 15 h 375
    2

, so the height is

25 cm.

91. Arc AB measures 76r, so m’APB =

1

2 (76) =

38 r.

92. m’QPR =

1

2 (301 – 59) =

1

2 (242) = 121r.

93. m’MXS = m’NXT =

1

2 (24 + 52) =

1

2 (76) =

38 r.

94. C = 2 v S v 7 = 14S cm.


95. Diameter is 24 cm, so r = 12 cm.
    A = S v 122 = 144S cm^2