A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.

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

The sum of the interior angles of a triangle is 180°:
180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 67° - 49° = 64°

According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:

c² = a² + b²
c² = 7² + 6²
c² = 49 + 36
c² = 85
c = \( \sqrt{85} \)

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 equal sign and the answer on the other.

-3c + 4 = \( \frac{c}{2} \)
2 x (-3c + 4) = c
(2 x -3c) + (2 x 4) = c
-6c + 8 = c
-6c + 8 - c = 0
-6c - c = -8
-7c = -8
c = \( \frac{-8}{-7} \)
c = 1\(\frac{1}{7}\)