Calculating the Area of a Triangle: Exploring the 0.5*b*h Formula

In summary, the conversation is about finding the area of a triangle. One person used the formula 0.5*b*h and got a different result than expected. Another person suggested using the midpoint and length of the sides to find the height and base, while someone else explained that this method may not always result in the correct measurement. They also mentioned using the altitude for the height instead. Ultimately, they thanked each other for their help and apologized for any mistakes in their grammar.
  • #1
phospho
251
0
Could anyone tell me how they found the area of the triangle?

f4YHe.png


When I try to use 0.5*b*h I get 10.64483443, not 10.5
 
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  • #2
They subtracted the areas of the three right triangles outside the given triangle from the area of the rectangle.

How did you calculate b and h for the triangle? I'm guessing you did it wrong.
 
  • #3
LCKurtz said:
They subtracted the areas of the three right triangles outside the given triangle from the area of the rectangle.

How did you calculate b and h for the triangle? I'm guessing you did it wrong.

I found the midpoint of the two bottom verticies of the triangle, then found the length from that midpoint to the top vertex and used that as the height. The length of the two bottom vertices I used as the base.

I see what they done now, thanks, but is how could I have done using the b*h*0.5?
 
  • #4
phospho said:
I found the midpoint of the two bottom verticies of the triangle, then found the length from that midpoint to the top vertex and used that as the height. The length of the two bottom vertices I used as the base.

I see what they done now, thanks, but is how could I have done using the b*h*0.5?

You mean "did".

The line from the midpoint of a side to the opposite vertex is a median. Medians are not generally perpendicular to the side, so its length is not the height of the triangle.

To do it that way you would have to find where the line from the vertex perpendicular to the other side intersects the other side and use that line (called the altitude) for the height.
 
  • #5
LCKurtz said:
You mean "did".

The line from the midpoint of a side to the opposite vertex is a median. Medians are not generally perpendicular to the side, so its length is not the height of the triangle.

To do it that way you would have to find where the line from the vertex perpendicular to the other side intersects the other side and use that line (called the altitude) for the height.

apologies for my bad grammar.

thanks for helping.
 

FAQ: Calculating the Area of a Triangle: Exploring the 0.5*b*h Formula

What is the formula to calculate the area of a triangle?

The formula to calculate the area of a triangle is 0.5 multiplied by the base (b) of the triangle and the height (h) of the triangle. This formula is commonly represented as A = 0.5*b*h.

How do you find the base and height of a triangle?

The base and height of a triangle can be found by measuring the length of the two sides that form a right angle, also known as the legs of the triangle. The base and height can also be calculated using the Pythagorean Theorem, where the hypotenuse (longest side) is the square root of the sum of the squares of the two legs.

Can the 0.5*b*h formula be used for all types of triangles?

Yes, the 0.5*b*h formula can be used for all types of triangles, including equilateral, isosceles, and scalene triangles. However, for triangles that are not right triangles, the base and height must be calculated differently.

Are there any other formulas for calculating the area of a triangle?

Yes, there are other formulas for calculating the area of a triangle, such as Heron's formula and the trigonometric formula. These formulas may be more appropriate for non-right triangles or for certain applications, but the 0.5*b*h formula is the most commonly used and easiest to remember.

Why is the 0.5*b*h formula used for calculating the area of a triangle?

The 0.5*b*h formula is used for calculating the area of a triangle because it is derived from the formula for calculating the area of a rectangle, which is base multiplied by height. Since a triangle can be divided into two equal right triangles, the formula for the area of a triangle is half of the formula for a rectangle, hence the 0.5 multiplier.

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