 So in this problem, we want to find the height of triangle CAB, given the fact that we know the base and the area. So first off, let's write the area formula for a triangle. Area is 1 half times base times height. And now in this particular formula, we know the area and we know the base and we want to solve for the height. So all that's left to do is to substitute in the values of the numbers we know and solve for what we don't. We know the area is 12. So 12 is equal to 1 half times base, which was 4 times height, which is unknown. So then let's simplify, 1 half times 4 is of course 2. So 12 is equal to 2 times h. And if you divide both sides of the equation by 2, you get that h is equal to 6 units. So let's add one more problem, kind of a bonus problem. We want to find the area of this triangle and we know nothing except the hypotenuse. We know it is a right triangle and in particular we know it's a right isosceles triangle. And remember right isosceles triangles are 45, 45, 90 triangles. And so if the hypotenuse is 10, that means 10 is equal to the n root 2 side. And so that means n must equal 5 root 2. And so our base and height, both are 5 square roots of 2. Oops, 5 root 2. And so if we use one as our base and the other as the height, the area is 1 half times base times height. We can multiply in whatever order we want so we can call this 1 half times root 2 times root 2 times 5 times 5. And root 2 times root 2. Well that's just the square root of 4, which is 2. So we have area is 1 half times root 2 times root 2 is equal to 2 times 5 times 5 which is 25. And then if we multiply straight across, we have area is 1 half times 2 is just 1 and 1 times 25 is just 25 square units.