The area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:

a = ½(b + d)(h)
a = ½(7 + 6)(4)
a = ½(13)(4)
a = ½(52) = \( \frac{52}{2} \)
a = 26

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

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

y² - 2y - 15 = 0
(y + 3)(y - 5) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (y + 3) or (y - 5) must equal zero:

If (y + 3) = 0, y must equal -3
If (y - 5) = 0, y must equal 5

So the solution is that y = -3 or 5

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

c² = a² + b²
c² = 2² + 6²
c² = 4 + 36
c² = 40
c = \( \sqrt{40} \)