An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:

d° = b° + c°

To find angle c, remember that the sum of the interior angles of a triangle is 180°:

180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 29° - 62° = 89°

So, d° = 62° + 89° = 151°

A shortcut to get this answer is to remember that angles around a line add up to 180°:

a° + d° = 180°
d° = 180° - a°
d° = 180° - 29° = 151°

A quadrilateral is a shape with four sides. The perimeter of a quadrilateral is the sum of the lengths of its four sides.

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.

The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

x² - 11x + 30 = 0
(x - 5)(x - 6) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (x - 5) or (x - 6) must equal zero:

If (x - 5) = 0, x must equal 5
If (x - 6) = 0, x must equal 6

So the solution is that x = 5 or 6

The volume of a cube is height x length x width:

v = h x l x w
v = 6 x 3 x 8
v = 144