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

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 2 x 1) + (2 x 1 x 5) + (2 x 2 x 5)
sa = (4) + (10) + (20)
sa = 34

Parallel lines are lines that share the same slope (steepness) and therefore never intersect. A transversal occurs when a set of parallel lines are crossed by another line. All of the angles formed by a transversal are called interior angles and angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°) and are called corresponding angles. Alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°) and all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other. Same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°).

You need to find the value of a so solve the first equation in terms of y:

9a + y = 9
y = 9 - 9a

then substitute the result (9 - 9a) into the second equation:

-7a + 7(9 - 9a) = 4
-7a + (7 x 9) + (7 x -9a) = 4
-7a + 63 - 63a = 4
-7a - 63a = 4 - 63
-70a = -59
a = \( \frac{-59}{-70} \)
a = \(\frac{59}{70}\)

The slope of this line is the change in y divided by the change in x. The endpoints of this line segment are at (-2, 0) and (2, 6) so the slope becomes: