CPM Homework Banner

Home > PC > Chapter 10 > Lesson 10.1.3 > Problem 10-43


Greg’s shadow is cast on a wall by a light on the ground which is meters from the wall. Greg is centimeters tall. Express the height (in meters) of his shadow, , as a function of his distance from the wall, .

Draw and label a diagram.

See diagram at right.
What expression would you use for the '?' ?

Right triangle, horizontal leg labeled 20, vertical leg labeled h, vertical segment labeled 1.8, between horizontal leg & hypotenuse, divides horizontal leg into 2 sections, section between vertical segment & vertical leg labeled, d, other section labeled question mark.

Write a proportion using the similar triangles in the diagram.

Now rewrite the equation in form.