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.

5a + 1 > \( \frac{a}{-1} \)
-1 x (5a + 1) > a
(-1 x 5a) + (-1 x 1) > a
-5a - 1 > a
-5a - 1 - a > 0
-5a - a > 1
-6a > 1
a > \( \frac{1}{-6} \)
a > -\(\frac{1}{6}\)

The surface area of a cube is (2 x length x width) + (2 x width x height) + (2 x length x height):

sa = 2lw + 2wh + 2lh
sa = (2 x 3 x 8) + (2 x 8 x 8) + (2 x 3 x 8)
sa = (48) + (128) + (48)
sa = 224

The formula for circumference is circle diameter x π:

c = πd
c = 6π

A trapezoid is a quadrilateral with one set of parallel sides.