Introduction to Trigonometry

What angle makes the green and red sides equal in length?

What angle makes the side adjacent to the angle (the red side) equal to 0.5?

As the angle increases in size, does the red side get longer or shorter?

As the angle increases in size, does the green side get longer or shorter?

When the angle is 20°, the green side is 0.342; the red side is 0.94. At what angle do they swap, that is, the red is 0.342 and the green is 0.94?

When the angle is 10°, the green side is 0.174; the red side is 0.985. At what angle do they swap, that is, the red is 0.342 and the green is 0.94?

Two angles can give a pair of congruent triangles. How are those angles related?

What does the Pythagorean theorem say about the green side, the red side and the number 1,for any angle? Give an example.

Suppose a right angled triangle has hypotenuse length 5 cm, and one of the angles is 25°. Use the applet above to figure out how long the other two sides would be.