Trigonometry Adventure
Step into an exciting journey where triangles come alive and every angle tells a story! Trigonometry Adventure by MedhāVatika transforms one of the most challenging math topics into a playful exploration.
Chapter 1
Degrees and Radians
Degrees (°): A common unit for measuring angles. A full circle is divided into 360 degrees.
Radians (rad): A mathematical unit for measuring angles based on the radius of a circle. A full circle is 2π radians.
Conversion Formulas:
To convert degrees to radians:
angle in degrees × (π / 180°)
To convert radians to degrees:
angle in radians × (180° / π)
Solutions to Exercise 1:
How many degrees are in π radians?
Since 2π radians = 360°, then π radians is half of that.
Answer: 180°
Convert 90° to radians.
Using the formula: 90° × (π / 180°) = 90π / 180 = π/2 radians.
Answer: π/2 radians
Convert π/3 radians to degrees.
Using the formula: (π/3) × (180° / π) = 180°/3 = 60°.
Answer: 60°
Chapter 2

The Six Trig Functions
SOH CAH TOA is a mnemonic for the three primary trigonometric functions in a right-angled triangle.
Sine (sin) = Opposite / Hypotenuse
Cosine (cos) = Adjacent / Hypotenuse
Tangent (tan) = Opposite / Adjacent
Reciprocal Functions: Each primary function has a reciprocal.
Cosecant (csc) = 1/sin = Hypotenuse / Opposite
Secant (sec) = 1/cos = Hypotenuse / Adjacent
Cotangent (cot) = 1/tan = Adjacent / Opposite
How Sin²θ + Cos²θ = 1?
sin²θ + cos²θ = 1
θ = 0° · 0 radsin²θ = 0.0000
cos²θ = 1.0000
Tip: drag the cyan point, use the slider, or press Play. The circle, waves, shaded integrals, and the 100% bar all stay in sync.
Chapter 4: Shape the wave
How does its period compare to a regular cosine wave? Is it shorter or longer?
Practical Applications
Navigation & mapping
GPS & geodesy: Convert satellite ranges to latitude/longitude using spherical trig; local ENU ↔ geodetic conversions.
Triangulation: Find your position by measuring angles to two known landmarks.
Aviation & marine: Course corrections with wind/current using vector components: vx=vcosθ, vy=vsinθv_x=v\cos\theta,\ v_y=v\sin\thetavx=vcosθ, vy=vsinθ.
Surveying, civil & architecture
Measuring heights/distances: Clinometer + baseline: height≈dtanθ+eye height \text{height} \approx d\tan\theta + \text{eye height}height≈dtanθ+eye height.
Road & rail design: Grades, curves, and superelevation (bank angle) from tan θ=v2/(rg)\tan\theta = v^2/(rg)tanθ=v2/(rg).
Roofs & stairs: Pitch and rise–run angles; stringer length via cosine rule.
Physics of motion (sports & ballistics)
Projectile motion: Range R=v2gsin2θR=\frac{v^2}{g}\sin 2\thetaR=gv2sin2θ; optimal launch angles for javelin, basketball arcs, free-kicks.
Spin & curve balls: Magnus effect depends on spin axis angle; components set with trig.
Golf/archery analytics: Decompose club/bow speed into launch speed & direction.