☰ Contents · Geometry

Sine, cosine, tangent and cotangent of an angle

Lessons 25 · 1 lessons · B. Xaydarov, E. Sariqov, A. Qo‘chqorov. Geometry, Grade 9 (textbook for general secondary schools), revised 4th edition. Huquq va Jamiyat Publishing, Tashkent, 2019
Answers are for parents and teachers.
1
Find sin120°.
2
Find cos135°.
3
sinα = 5/13 and α is acute. Find cosα.
4
If sinα = 1/2, find both values of α (0° ≤ α ≤ 180°).
5
Why is the tangent of an obtuse angle negative?