Check the wrench before any trig question. Desmos in the wrong angle mode will graph a confident, incorrect curve. ACT Math problems that mention degrees need degree mode. The calculator itself is covered in Desmos on the ACT.
Where the switch is
Open the graph settings, the wrench icon, and choose degrees or radians. Leave it on degrees unless the question says radians or gives an angle in terms of π. sin(30) in degree mode is 1/2. In radian mode it is not. That single miss can knock out a whole question.
Right-triangle ratios, which do not need a mode switch if you are not graphing, are in right-triangle trigonometry.
Do not assume the default
The testing build does not remember a mode you set on the public Desmos site at home. What else that build turns off is in disabled Desmos features. Practicing in the locked-down tool is in practicing the locked Desmos.
The bottom line
Wrench, then degrees, unless the problem is written in radians. Check it before you trust the graph.
Start practicing
Start with a free diagnostic, then drill your weak spots with 15-question quizzes and track how you're doing across Reading, English, and Math. Compare plans whenever you're ready to go further.
This article offers general ACT prep guidance. The ACT can change from year to year, including its format, scoring, policies, test dates, and fees, so always confirm the latest details on the official ACT website at act.org before you make decisions. ACT® is a registered trademark of ACT, Inc. thirty-six is not affiliated with, endorsed by, or sponsored by ACT.