🎯

Learning Goal

‹5 of 6 in this skill_area›

Complementary angle relationship (sin x = cos(90 degrees - x))

Start lessonBegins with Exercise · Practice

Teacher tools for this standard

Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework

"Solve problems using the relationship between sine and cosine of complementary angles."

Show more

"Solve problems using the relationship between sine and cosine of complementary angles."

What you'll learn

  1. Solve problems using the relationship between the sine and cosine of complementary angles: sin(x) = cos(90° − x) and cos(x) = sin(90° − x) for acute angles x
  2. Explain why these identities hold by analyzing the two acute angles in a right triangle
  3. Determine an unknown angle from an equation of the form sin(x) = cos(y), including angles given as linear expressions (e.g., if sin(x) = cos(35°), find x)
  4. Use the relationship to rewrite an expression, check an equivalence, and read cos(B) from sin(A) for the acute angles of a right triangle

Slides

Step through the lesson, or watch it as a narrated video

Slides

In development

Not yet available • Check back soon!

Practice

Try it on your own

Was this lesson helpful?
Report a problem with this page