Lines, Angles and Triangles on the Digital SAT: the Desmos Method
Every one of these questions is a geometry fact you have to know, followed by arithmetic you should not do in your head. Name the fact, write the one line of numbers it gives you, and let Desmos finish it.
Geometry & Trigonometry·65 practice problems in DesPrep
The Lines, Angles and Triangles lesson is part of DesPrep
It is one of the 17 full lessons inside the subscription — 7 sections that take lines, angles and triangles from first principles to the fastest Desmos route, with a worked example on every one:
- Desmos does not know any geometry
- A straight line is 180. A right angle is 90.
- The third angle, in one line
- Distance between two points is a right triangle you cannot see
- Similar triangles: the letters tell you what matches
- A parallel cut splits both sides the same way
- The altitude onto the hypotenuse — the one that wants a graph
Then 65 practice problems on this skill alone, solved inside a live Desmos calculator with step feedback and an expert replay on every one.
More Geometry & Trigonometry guides
- Area and VolumeArea and volume formulas evaluated in Desmos, including the maximum-area problems that are really parabolas in disguise.
- CirclesCenter, radius and extreme points of a circle — graphed as a semicircle when the answer is a point you can click.
- Right Triangles and TrigonometryPythagorean triples and the three ratios, kept exact as fractions.