Here are the marks 18 students got in a Maths test. 46 65 54 57 62 73
73 47 69 48 63 68
55 48 58 71 76 70
a) Show this information in an
ordered stem and leaf diagram.
(3)

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.