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.

The area of a rectangle is equal to its length x width:

a = l x w
a = a x b
a = 7 x 2
a = 14

A parallelogram is a quadrilateral with two sets of parallel sides. Opposite sides (a = c, b = d) and angles (red = red, blue = blue) are equal. The area of a parallelogram is base x height and the perimeter is the sum of the lengths of all sides (a + b + c + d).

To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the > sign and the answer on the other.

-7b + 6 > \( \frac{b}{-5} \)
-5 x (-7b + 6) > b
(-5 x -7b) + (-5 x 6) > b
35b - 30 > b
35b - 30 - b > 0
35b - b > 30
34b > 30
b > \( \frac{30}{34} \)
b > \(\frac{15}{17}\)

A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.