Hello there! We are looking for the height of the tree. To find the height of the tree, we can write and solve a proportion. Set it up like this:
64/72 = x/144
This is because we know the shadow for both you and the tree, but we are looking for the heigh of the tree. This is the proper way to get you to the correct answer with ease. Let's start off by cross multiplying the values. 144 * 64 is 9,216. 72 * x is 72x. That's 9,216 = 72x. Now, divide each side by 72 to isolate the x. 72x/72 cancels out. 9,216/72 is 128. There. x = 128. The tree is 128 inches tall. The answer is B: 128 in.
