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Attachment:
2017-11-21_1004.png
2017-11-21_1004.png [ 9.87 KiB | Viewed 2391 times ]

From the figure, in line AB, the sum of angles is 180, which makes angle x = 180 - 135 = 45
Similarly, the sum of angles in line XY is also 180, making angle y = 45

We can also say that y=45 because x and y are vertically opposite angles.

Hence, x+y = 90(Option C)
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Bunuel

If C is the center of the circle above, then x + y =

(A) 45
(B) 65
(C) 90
(D) 100
(E) 130

Attachment:
2017-11-21_1004.png
135+y = 180

So, y = 45

Further x = y = 45

Hence, x + y = 90 , answer will be (C)
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Bunuel

If C is the center of the circle above, then x + y =

(A) 45
(B) 65
(C) 90
(D) 100
(E) 130

Attachment:
2017-11-21_1004.png


Hi..
Bunuel, may be specifying that the two lines are straight lines would clarify the question a bit more, otherwise it could be just four radius drawn from center
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chetan2u
Bunuel

If C is the center of the circle above, then x + y =

(A) 45
(B) 65
(C) 90
(D) 100
(E) 130

Attachment:
2017-11-21_1004.png


Hi..
Bunuel, may be specifying that the two lines are straight lines would clarify the question a bit more, otherwise it could be just four radius drawn from center

OFFICIAL GUIDE:

Problem Solving
Figures: All figures accompanying problem solving questions are intended to provide information useful in solving the problems. Figures are drawn as accurately as possible. Exceptions will be clearly noted. Lines shown as straight are straight, and lines that appear jagged are also straight. The positions of points, angles, regions, etc., exist in the order shown, and angle measures are greater than zero. All figures lie in a plane unless otherwise indicated.
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Bunuel

If C is the center of the circle above, then x + y =

(A) 45
(B) 65
(C) 90
(D) 100
(E) 130

Attachment:
2017-11-21_1004.png

A circle contains 360 degrees, and a semicircle contains 180 degrees. We see that both 135 + x = 180 and 135 + y = 180, so both x and y are 45; thus, x + y = 90.

Answer: C
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