1. **State the problem:** Find the coordinates of the orthocenter of the triangle with vertices at points $A(0,0)$, $B(8,2)$, and $C(2,3)$. The orthocenter is the point where the three altitudes of the triangle intersect.
2. **Recall the formula and rules:**
- An altitude is a perpendicular line from a vertex to the opposite side.
- To find the orthocenter, find equations of two altitudes and solve their system.
3. **Find slope of side $BC$:**
$$m_{BC} = \frac{3 - 2}{2 - 8} = \frac{1}{-6} = -\frac{1}{6}$$
4. **Find slope of altitude from $A$ (perpendicular to $BC$):**
$$m_{A} = -\frac{1}{m_{BC}} = -\frac{1}{-\frac{1}{6}} = 6$$
5. **Equation of altitude from $A(0,0)$:**
$$y = 6x$$
6. **Find slope of side $AC$:**
$$m_{AC} = \frac{3 - 0}{2 - 0} = \frac{3}{2}$$
7. **Find slope of altitude from $B$ (perpendicular to $AC$):**
$$m_{B} = -\frac{1}{m_{AC}} = -\frac{1}{\frac{3}{2}} = -\frac{2}{3}$$
8. **Equation of altitude from $B(8,2)$:**
Use point-slope form:
$$y - 2 = -\frac{2}{3}(x - 8)$$
Simplify:
$$y = -\frac{2}{3}x + \frac{16}{3} + 2 = -\frac{2}{3}x + \frac{16}{3} + \frac{6}{3} = -\frac{2}{3}x + \frac{22}{3}$$
9. **Find intersection of altitudes (orthocenter):**
Set
$$6x = -\frac{2}{3}x + \frac{22}{3}$$
Multiply both sides by 3 to clear denominators:
$$3 \times 6x = 3 \times \left(-\frac{2}{3}x + \frac{22}{3}\right)$$
$$18x = -2x + 22$$
Add $2x$ to both sides:
$$18x + 2x = 22$$
$$20x = 22$$
Divide both sides by 20:
$$x = \frac{22}{20} = \frac{11}{10}$$
10. **Find $y$ coordinate:**
$$y = 6x = 6 \times \frac{11}{10} = \frac{66}{10} = \frac{33}{5}$$
**Final answer:** The orthocenter is at $$\left(\frac{11}{10}, \frac{33}{5}\right)$$.
Orthocenter Coordinates 9791Ab
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