The formula for the area of a triangle is given by:
Area = 1/2 x base x height
Here, base and height are the two important parameters we need to calculate the area of a triangle. The base is one of the sides of the triangle, and the height is the perpendicular distance from the opposite vertex of the base.
To understand the formula, let’s take an example. Suppose we have a triangle ABC, where AB=10 cm, BC=12 cm, and AC=8 cm. We need to calculate the area of this triangle.
First, let’s find the base and height of the triangle. Let’s take AB as the base. The height is the perpendicular distance from the vertex C to the line AB. To find the height, we can draw a perpendicular line from vertex C to line AB. This line will intersect AB at a point D.
Now, we need to find the length of CD. We know that triangle ACD is a right-angled triangle. So, we can use Pythagoras theorem to find CD. Applying Pythagoras theorem, we get:
CD^2 = AC^2 – AD^2
= 8^2 – 6^2
= 64 – 36
= 28
CD = √28
CD ≈ 5.29 cm
So, the height of the triangle is 5.29 cm.
Now, we can use the formula for the area of a triangle:
Area = 1/2 x base x height
= 1/2 x AB x CD
= 1/2 x 10 x 5.29
= 26.45 cm²
So, the area of the triangle ABC is 26.45 cm².
There are other methods to find the area of a triangle. For example, if we know the length of all three sides of the triangle, we can use Heron’s formula. Heron’s formula is given by:
Area = √s(s-a)(s-b)(s-c)
Here, s is the semiperimeter of the triangle, which is half the sum of the length of all three sides. a, b, and c are the lengths of the three sides of the triangle. This formula is useful when we don’t know the height of the triangle.
Another method to find the area of a triangle is by using vectors. If we know the position vectors of the three vertices of a triangle, we can use the cross product of two vectors to find the area of the triangle. This method is useful when we are dealing with non-right-angled triangles.
In conclusion, the area of a triangle is an important concept in mathematics. We use it to solve various problems in different fields. We can find the area of a triangle by using different methods, depending on the information we have. Regardless, the formula 1/2 x base x height is a simple and easy-to-use method that can always come in handy.