For parallel lines with a transversal, the following relationships apply:

• angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°)
• alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°)
• 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°)

Applying these relationships starting with w° = 20, the value of a° is 20.

The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)² : a = π r².

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, 5) and (2, 1) so the slope becomes:

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, isolate the variable for which you are solving (a) on one side of the equation and put everything else on the other side.

-9a - 6z = 2a + 5z + 3
-9a = 2a + 5z + 3 + 6z
-9a - 2a = 5z + 3 + 6z
-11a = 11z + 3
a = \( \frac{11z + 3}{-11} \)
a = \( \frac{11z}{-11} \) + \( \frac{3}{-11} \)
a = -z - \(\frac{3}{11}\)