Enter any angle θ and choose the relationship type. Get the related angle instantly with a visual diagram and step-by-step explanation.
Complementary: Two angles that add to 90°. Each is the complement of the other.
Supplementary: Two angles that add to 180°. They form a straight line.
Vertical: Opposite angles formed by two intersecting lines. Always equal.
Co-interior: Same-side interior angles between parallel lines. Always supplementary.
Complementary: θ + x = 90° → x = 90 − θ
Supplementary: θ + x = 180° → x = 180 − θ
Vertical: x = θ
Co-interior: θ + x = 180° → x = 180 − θ
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