MHB Calculate the area of a triangle knowing its 3 heights

  • Thread starter Thread starter loquetedigo
  • Start date Start date
  • Tags Tags
    Area Triangle
AI Thread Summary
The discussion focuses on calculating the area of a triangle using its three heights, specifically ha = 3 m, hb = 4 m, and hc = 5 m. Participants are prompted to consider the use of Heron's formula and the semi-sum of the reciprocals of the altitudes to derive the area. The area is estimated to be around 10.03 m² to 10.05 m², with a note that using an online calculator like TrianCal can assist in visualizing the results. The conversation emphasizes the mathematical relationships between the triangle's heights and its area. Accurate calculations are essential for determining the correct area based on the given heights.
loquetedigo
Messages
12
Reaction score
0
Calculate the area of a triangle knowing its 3 heights

ha = 3 m
hb = 4 m
hc = 5 m

NOTE = You can use the online triangle calculator TrianCal to see and draw the results.
NOTE = Do not use the values ??of responses.

A) 10.03 m2
B) 10.04 m2
C) 10.05 m2
D) Imposible
 
Mathematics news on Phys.org
greg1313 said:
Can you apply Heron's formula?
thanks...
Next, denoting the altitudes from sides a, b, and c respectively as ha, hb, and hc, and denoting the semi-sum of the reciprocals of the altitudes as H = (h_a^{-1} + h_b^{-1} + h_c^{-1})/2 we have[11]

A^{-1} = 4 \sqrt{H(H-h_a^{-1})(H-h_b^{-1})(H-h_c^{-1})}.
 
Last edited:
Seemingly by some mathematical coincidence, a hexagon of sides 2,2,7,7, 11, and 11 can be inscribed in a circle of radius 7. The other day I saw a math problem on line, which they said came from a Polish Olympiad, where you compute the length x of the 3rd side which is the same as the radius, so that the sides of length 2,x, and 11 are inscribed on the arc of a semi-circle. The law of cosines applied twice gives the answer for x of exactly 7, but the arithmetic is so complex that the...
Back
Top