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 perimeter of a triangle is the sum of the lengths of its sides:

p = x + y + z
p = 9cm + 13cm + 5cm = 27cm

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

c² = a² + b²
c² = 2² + 8²
c² = 4 + 64
c² = 68
c = \( \sqrt{68} \)

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 + y - 56 = 0
(y - 7)(y + 8) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (y - 7) or (y + 8) must equal zero:

If (y - 7) = 0, y must equal 7
If (y + 8) = 0, y must equal -8

So the solution is that y = 7 or -8