Answer:
Radius of the circle is <em>15 inches.</em>
<em></em>
Step-by-step explanation:
Relation between length of arc, radius and the angle subtended by the arc on center is:

where
is the central angle in radians subtended by arc
is the length of arc
is the radius of arc
We are Given the following details:


We know that 
Converting
to radians:
radians
Putting the values of
and
to find the value of 

Hence, Radius of the circle is <em>15 inches.</em>
the SAS similarity theorem
Since 1 km = 1000 m, the lawnmowers top speed would be 8000 m/h.
I need to know how many miles the race is
ANSWER

EXPLANATION
Since the directrix is

the axis of symmetry of the parabola is parallel to the y-axis.
Again, the focus being,

also means that the parabola will open upwards.
The equation of parabola with such properties is given by,

where

is the vertex of the parabola.
The directrix and the axis of symmetry of the parabola will intersect at

The vertex is the midpoint of the focus and the point of intersection of the axis of the parabola and the directrix.
This implies that,

and

The equation of the parabola now becomes,


Thus, the distance between the vertex and the directrix.
This means that,

Since the parabola opens up, we choose

Our equation now becomes,

This simplifies to

or

This is the same as,

The correct answer is D .