The area of a triangle is simple you just need to know a formula, and then just know the parts that fit into the formula so that you can solve it. So let’s look at the formula. The area of a triangle is one half the base times the height and that represents the area. So H is our height, but our height is really an altitude drawn from the peak down to the base which is the reference side of that altitude touches.

When you have a right triangle the one half times base times’ height is so simple. So let’s do that one first. We have a side of three and notice we have a right angle here. So that means that is the same as my altitude or my height. So three is my height so I will plug 3 in for my H. It touches the side that is the base of 4 so 4 is my base. So I will multiple 4 times 3 to get 12 and then half of 12 is 6 So the area of this triangle is 6 units.

Let’s look at an acute triangle. All three angles are less than 90 so it is acute. We have an altitude drawn and the altitude is 8 and it touches this base which is 5 So I just multiple the base which 5 times the altitude which is 8 which is 40 and half of 40 is twenty so this one is 20 square inches

Finally let’s look at an obtuse triangle Let’s use the formula for the area of a triangle 1/2base * height

Find the area of a triangle with a height of 5 and a base of 6. So let’s plug in one half base times height so one half 6 which is my base and my height is 5, 5 times 6 is 30 and one half 30 is 15 units