Mathematics SAT-80: Completing the Square to Find a Circle's Center and Radius Turn an expanded circle equation into standard form by completing the square for x and for y.
Mathematics SAT-79: Circle Equations in the Coordinate Plane Read the center and radius straight from the standard circle equation (x − h)² + (y − k)² = r².
Mathematics SAT-78: Area of a Sector of a Circle Find the area of a 'pizza slice' sector as a fraction of the whole circle's area.
Mathematics SAT-77: Radians vs. Degrees and Arc Length Convert between radians and degrees and compute arc length as a fraction of the circle's circumference.
Mathematics SAT-76: Trigonometric Identities — sin(x) = cos(90° − x) Use the cofunction identity sin(x) = cos(90° − x) to connect the sine and cosine of complementary angles.
Mathematics SAT-75: Right Triangle Trigonometry — Sine, Cosine, Tangent Use SOH-CAH-TOA to relate the sides and angles of a right triangle and solve for unknowns.
Mathematics SAT-74: Congruent Triangles and Area/Perimeter Scaling Tell congruent from similar figures, and scale perimeter by k and area by k² when sizes change.
Mathematics SAT-73: Triangle Inequality and Similarity (AA, SAS) Use the triangle inequality to test side lengths and AA/SAS to prove triangles are similar.
Mathematics SAT-72: Special Right Triangles — 30-60-90 Use the fixed 1 : √3 : 2 side ratio of a 30-60-90 triangle to find any side from one side.
Mathematics SAT-71: Special Right Triangles — 45-45-90 Use the fixed side ratio 1 : 1 : √2 of a 45-45-90 triangle to find sides without the full theorem.
Mathematics SAT-70: Pythagorean Theorem and the Distance Formula Use a² + b² = c² for right triangles and apply it as the distance formula on the coordinate plane.
Mathematics SAT-69: Isosceles and Equilateral Triangles Use the base-angles property of isosceles triangles and the all-60° rule of equilateral triangles.