A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).

The area of a triangle is equal to ½ base x height:

a = ½bh
a = ½ x 3 x 4 = \( \frac{12}{2} \) = 6

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 parallelogram is equal to its length x width:

a = l x w
a = a x b
a = 3 x 1
a = 3

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

-5a + y = -2
y = -2 + 5a

then substitute the result (-2 - -5a) into the second equation:

4a - 8(-2 + 5a) = 8
4a + (-8 x -2) + (-8 x 5a) = 8
4a + 16 - 40a = 8
4a - 40a = 8 - 16
-36a = -8
a = \( \frac{-8}{-36} \)
a = \(\frac{2}{9}\)