Answer: 48
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Step-by-step explanation:
Triangle ABC is isosceles because AC = BC.
The angles opposite these congruent sides are angle ABC and angle BAC. These are the base angles.
For any isosceles triangle, the base angles are congruent.
Angle BAC = 69 degrees is given. So angle ABC = 69 as well.
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The missing angle must add to the two other angles so that all three angles in a triangle add to 180
(angle ABC) + (angle BAC) + (angle BCA) = 180
69 + 69 + (angle BCA) = 180
138 + (angle BCA) = 180
angle BCA = 180-138
angle BCA = 42
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Angle DCE is congruent to angle BCA because they are vertical angles.
Triangle DCE is a right triangle. The missing angle is 90-(angle BCA) = 90-42 = 48
angle EDC = 48 degrees