Why does atan2 matter?	It uses both coordinate differences so the angle lands in the correct quadrant.	topicladder math math
What should you check before using sin or cos in code?	Check whether the angle is in radians or degrees.	topicladder math math
What does the 'Name the triangle or circle' step prove?	Trig answers a relationship between angle and length, so start with the shape. Check: The sketch shows the angle and the known side or radius.	topicladder math math
What does the 'Choose the right function' step prove?	Sine, cosine, tangent, and atan2 answer different questions. Check: You can say which unknown each function is solving.	topicladder math math
What does the 'Respect radians and degrees' step prove?	Game engines and math libraries often use radians while people describe angles in degrees. Check: Your note names the unit before calculation.	topicladder math math
What does the 'Check the quadrant' step prove?	atan2 keeps sign information that plain atan can lose. Check: The result points in the expected direction on the drawing.	topicladder math math
When would you use `x = cos(angle) * radius; y = sin(angle) * radius`?	Use it to place a point around a circle. Expected signal: The point moves around the origin at the chosen radius	topicladder math command
When would you use `angle = atan2(target_y - y, target_x - x)`?	Use it to find the angle from one point to another. Expected signal: The angle points from the current point to the target	topicladder math command
When would you use `rise = tan(angle) * run`?	Use it to estimate rise from angle and run. Expected signal: The computed rise matches the sketched slope direction	topicladder math command
Where can you review the full Trigonometry for Rotation and Layout context?	Use the TopicLadder page for the text lesson, examples, downloads, and practice task: https://topicladder.com/learn/trigonometry-for-rotation-and-layout/	topicladder math math source