The area of a triangle can be determined by multiplying half of the base by the height, as a triangle is essentially half of a quadrilateral shape. Calculate the area of a triangle with instructions from a college-level math teacher in this free video on geometry.
So how does one find the area of a triangle? Hi, I'm Jimmy Chang. I've been teaching college mathematics for 9 years and once you understand how the area of a triangle formula works, you understand what parts that you need and once you have the parts you can go from there. Now, here's the formula for the area of a triangle. It's A equals one half b, stands for h, which is height. So in other words, area is one half the base times the height. Now, if you have a triangle, such as a right triangle, everything is going to be pretty straight forward because in a right triangle, the base using 4 feet as an example, and the height, 6 feet as an example... in a right triangle, the height and base can be readily given. So in this case if you want to find the area of this triangle, you have a is equal to one half, the base is the flat side, 4 feet, times the height, which is 6 feet. And you're ready to go. Half of 4 feet is 2 feet, times 6 feet. Now you want to keep the units in there because measuring area requires square units. So 2 times 6 is going to be 12, but feet times feet is indeed feet squared or square feet. So the area of this particular triangle is 12 square feet. Now, if you don't have a right triangle, then here's this strategy. As long as you're given the base and the height, you're good to go. Again, plug it in, A equals one half, the base is 10 feet, the base is 5 feet, now half of 10 is 5, so you have 5 feet times 5 feet, now again multiply the numbers 5 times 5, which is 25, but always multiply the feet so we have the correct units, feet times feet, is feet squared or square feet, so the area of this particular triangle that's not a right triangle is 25 square feet. So, I'm Jimmy Chang and these are a couple of examples as to how to find the area of a triangle.