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 trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:

a = ½(b + d)(h)
a = ½(8 + 3)(5)
a = ½(11)(5)
a = ½(55) = \( \frac{55}{2} \)
a = 27\(\frac{1}{2}\)

A quadrilateral is a shape with four sides. The perimeter of a quadrilateral is the sum of the lengths of its four sides.

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.

7x - 7 > \( \frac{x}{-6} \)
-6 x (7x - 7) > x
(-6 x 7x) + (-6 x -7) > x
-42x + 42 > x
-42x + 42 - x > 0
-42x - x > -42
-43x > -42
x > \( \frac{-42}{-43} \)
x > \(\frac{42}{43}\)

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

a = l x w
a = a x b
a = 7 x 8
a = 56