Consider this diagram.
(6x+30)
(8x+10)
Given: m/CEA (8+10): m/AED
Prove: - 10
Statement
Part A
Mr. Avila asked his students to write either a two-column proof or a paragraph proof for the question shown.
Student A and Student B each made a mistake in their proof. Identify each student's mistake and the step in which they
made it.
Type your response in the box.
mZCRA
mZAED
838°
ZCEA and ZAED are a near
pair.
m/CEA + m/AED
8z + 10 + 6x + 30
14x + 40 180
14 140
-10
Student A's Proof
and
=
180°
L 180
(6m+30)
Reason
given
definition of linear pair
Linear pairs are
supplementary.
substitution
Like terms can be combined.
addition property of equality
division property of equality
Student B's Proof
We are given that mZCEA (8 + 10) and
m/AED = (6x +30) By the definition of vertical
angles, we know that ZCEA and ZAEDare vertical
angles. Vertical angles have equal measures, so
m/CEA m/AED substituting
m/CEA -
3x + 10and m/AED - 6x + 30 into
m/CEA
ZAED, we get
8+10= 6z+ 30. Using the subtraction property
of equality on the variable terms, this becomes
2z+10 30. Using the subtraction property of
equality on the constants, we get 2z - 20 By the
division property of equality, we prove that m 10
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