In <span>equilateral triangle all sides are equal =x,
from right triangle that is formed by </span>apothem , height 7*3= 21
hypotenuse /opposite leg = sin angle,
hypotenuse is a side of triangle =x, opposite leg is apotheme =21,
angle in equilateral triangle =60⁰
21/x= sin 60, x*sin60=21, x=21/sin60, x=21/(√3/2), x=42/√3
Area of triangle =1/2 x*x*sin angle
Area of triangle =1/2 *42/√3*42/√3*sin 60=1/2*(42²/3)*(√3/2) ≈ 255 cm²
this is just second way to do this problem, that I did at first (either way is correct)
<span> apothem divides one side by half,
so we get small right triangle with sides x hypotenuse, x/2 is one leg , and 21 is another leg
</span>by Pythagorean theorem
x²=(x/2)² +21²
x²-x²/4=441
3x²/4=441
3x²=441*4=1764
x²=1764/3
x=42/√3
Area of triangle =1/2*base *height =1/2*42/√3 *21≈255 cm²
Answer:
Vertex: (0, 0)
Focus: (0,
)
axis of symmetry:
= 0
Directrix:
= 
solution(s):
= 0
Step-by-step explanation:
Vertex:
The equation for a parabola is y = a(x - h)² + k
the vertex is the point (h, k), so in this equation the vertex is (0, 0)
Focus:
The equation for the focus of a vertical parabola is 4p(y - k) = (x - h)²
(p is the distance from the vertex to the parabola)
axis of symmetry:
The axis of symmetry is a vertical line that divides the parabola into two equal halves.
In this instance, because the vertex is (0, 0), the axis of symmetry is
= 0
Directrix:
The directrix is the point that is an equally far from the vertex as the focus is. Because this is the case, it would be the opposite of the focus, making the directrix 
Solution:
The only solution is
= 0 because the parabola only touches the x-axis once at the vertex
Answer:74=18+26+x
×=44+74
X=118
Step-by-step explanation: