Part 1)
Find m∠a
m∠a=54° --------> by vertical angles
Find m∠b
m∠b=54° --------> by corresponding angles
Find m∠c
m∠c=m∠a=54°-----> by corresponding angles
or
m∠c=m∠b=54° --------> by vertical angles
therefore
the answer part 1) is equal to
a) the measure of angle a is 54°
b) the measure of angle b is 54°
c) the measure of angle c is 54°
Part 2)
Find m∠d
we know that
m∠d=65° --------> by corresponding angles
Find m∠c
m∠d+m∠c=180° -----> by supplementary angles
solve for m∠c
m∠c=180-m∠d-------> m∠c=180-65°=115°
m∠c=115°
Find m∠b
m∠b=m∠d=65° -------> by alternate exterior angles
Find m∠a
we know that
m∠a+m∠b=180 -------> by consecutive interior angles
m∠a=180- m∠b---------> m∠a=180- 65-----> m∠a=115°
therefore
the answer Part 2) is
a) The measure of angle a is 115°
b) The measure of angle b is 65°
c) The measure of angle c is 115°
d) The measure of angle d is 65°
Part 3)
Let
x--------> the angle unknown ( see the attached figure to better understand the problem)
Find m∠x
we know that
m∠x=54° -------> by corresponding angles
Find m∠a
(2*m∠x)+(m∠a)=180 -------> by supplementary angles
m∠a=180-2*m∠x------> m∠a=180-2*54°----->m∠a=72°
Find m∠b
(m∠a+m∠x)=m∠b ------> by corresponding angles
m∠b=72°+54°-------> m∠b=126°
therefore
the answer Part 3) is
a) The measure of angle a is 72°
b) The measure of angle b is 126°
c) The measure of angle x is 54°