Math Lab
← All labs

Angle Explorer

Geometry · Class VI

Pick an angle from 0 to 360 and see its complement, supplement and reflex.

30 deg
type a value
0360
Live values
  • Complement60
  • Supplement150
  • Reflex330
  • Radians0.5236
Live readout
Complement60
Supplement150
Reflex330
Radians0.5236
Angle t (degrees)30 deg

Formulas in this lab

  • Complement
    90−t90 - t
  • Supplement
    180−t180 - t
  • Reflex
    360−t360 - t
  • Radians
    t⋅π180t \cdot \dfrac{\pi}{180}
Tip: Complements only make sense for acute angles (t between 0 and 90).

Frequently asked questions

▶What are complementary, supplementary and reflex angles?

Two angles are complementary if they add to 90 degrees and supplementary if they add to 180. The reflex angle of t is 360 - t, which is what is left after going around. So for t = 30, complement is 60, supplement is 150 and reflex is 330.

▶How do I use the angle explorer lab?

Slide t between 0 and 360 degrees. The lab shows 90 - t (complement), 180 - t (supplement) and 360 - t (reflex). Try t = 45 to see complement 45, supplement 135 and reflex 315.

▶How do angles show up around me?

The hands of a wall clock make changing angles all day. At 3 oclock the angle is 90 degrees, at 6 it is 180, and at 12 they overlap at 0. The lab lets you test other angle pairs you spot, like the slant of a kite or a ladder against a wall.

▶Complement vs supplement: how do I remember which is which?

C comes before S in the alphabet, and 90 comes before 180. So complement pairs with the smaller 90 and supplement pairs with the larger 180. The lab makes the difference visual: 90 - t shrinks fast, while 180 - t shrinks slower as you slide t.