SOLUTION: In triangle ABC, the orthocenter H lies on altitude \overline{AD}. Find \frac{AH}{HD}.

Algebra.Com
Question 1210491: In triangle ABC, the orthocenter H lies on altitude \overline{AD}. Find \frac{AH}{HD}.
Answer by CPhill(2136)   (Show Source): You can put this solution on YOUR website!
The ratio $\frac{AH}{HD}$ is $\mathbf{2}$.
Here is the reasoning based on the properties of an equilateral triangle:
## Orthocenter and Centroid in an Equilateral Triangle
In any triangle, the **orthocenter** ($H$) is the intersection point of the altitudes. The **centroid** ($G$) is the intersection point of the medians.
1. **Coincident Centers:** In an **equilateral triangle** ($\triangle ABC$):
* The median from any vertex is also the altitude from that vertex.
* This means the orthocenter ($H$), the centroid ($G$), the circumcenter, and the incenter all coincide at the same point.
* Therefore, the orthocenter $H$ is the same point as the centroid $G$.
2. **Median Property:** $\overline{AD}$ is an altitude (given) and, because the triangle is equilateral, it is also a median. The centroid ($G$ or $H$) divides any median into two segments in a ratio of $\mathbf{2:1}$.
[Image of a triangle and its medial triangle with area ratio labeled]

3. **Ratio Calculation:** The segment connecting the vertex ($A$) to the centroid ($H$) is twice as long as the segment connecting the centroid ($H$) to the midpoint ($D$) of the opposite side ($\overline{BC}$).
$$AH = 2 \cdot HD$$
Therefore, the ratio is:
$$\frac{AH}{HD} = \mathbf{2}$$

RELATED QUESTIONS

Given: ∆ABC –iso. ∆, m∠BAC = 120° AH ⊥ BC , HD (answered by MathLover1,greenestamps)
In triangle ABC, \angle A = 90^\circ. Altitude $\overline{AP},$ angle bisector... (answered by CPhill)
In the diagram, \overline{AD} is an altitude, \overline{BE} is a median, and... (answered by CPhill)
In the diagram, \overline{AD} is an altitude, \overline{BE} is a median, and... (answered by CPhill)
In the diagram below, ABCD is a rectangle with AD=6 and B=10. Point M is the... (answered by CPhill,ikleyn)
In △ABC, AC = BC, AB = 6, m∠BAC = 71º. Find the length of the altitude AH. (answered by josgarithmetic,ikleyn)
in an acute Triangle ABC, an altitude AD is drawn. Find the area of triangle ABC if AB=... (answered by richwmiller)
In an acute triangle ABC,an altitude AD is drawn. Find the area of triangle ABC if AB=15, (answered by mananth)
In right triangle abc, altitude ab. if ad = 8 cm and bd = 18 cm, find... (answered by jerryguo41)