The shadow of an object varies directly as its heights. A man 1.4meter tall cast a shadow 0.7m at the same time. A tree casts a shadow of 1.3m. How high is the tree?

According to the situation, the height of a man is directly proportional to the shadow of a tree and the shadow of a man is directly proportional to the height of a tree. Let us use the proportion in solving the problem and use x to determined the height of a tree.

• 1.4m (height of a man)
• 0.7 m (shadow of a man)
• 1.3m (shadow of a tree)
• x = ? (height of a tree)

To calculate the height of a tree, we must multiply the height of a man(1.4m) by the shadow of a tree(1.3m) divided by the shadow of a man(0.7m).

• =

• =

Therefore, the height of the tree is 2.6m

Check if both proportions will have the same product.

They are now proportional!