A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.

An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.

A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.

To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -35 as well and sum (Inside, Outside) to equal 2. For this problem, those two numbers are -5 and 7. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² + 2y - 35
y² + (-5 + 7)y + (-5 x 7)
(y - 5)(y + 7)

A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).