Pythagorean identity
Grade 11-12
What this lesson shows
From our triangle, sine of theta is 0.6 and cosine is 0.8. Square them both… and watch what they add up to.
Try it yourself
Real questions from this lesson's worksheets — answers below each one.
- cos θ = 4/5. Find sin θ (acute angle)
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3/5 - sin θ = 20/29. Find cos θ (acute angle)
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21/29 - Convert π/3 radians to degrees
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60° - Convert 3π/2 radians to degrees
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270°
Practise this every day
Eduyro gives your child a short daily worksheet on exactly this skill, and moves them on only once they have it. Watch the lesson, then build the fluency.
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