Proportions in Similar Figures

To find the height of a very tall pine tree, you place a mirror on the ground and stand where you can see the top of the pine tree.  How tall is the tree? Hint: the figures are similar triangles.

• 8 feet

• 72 feet

• 36 feet

• 144 feet

Review the picture. Find the missing side measurement in the picture using a proportion.

• x = 900 m

• x = 52 m

• x = 25 m

• x = 0.04 m

Solve for X.

• 2 ft

• 3 ft

• 4 ft

• 6 ft

Find y.

• 144

• 18

• 72

• 12

The shapes are similar. Use proportions to find the value of x.

• x = 12 inches

• x = 7 inches

• x = 6 inches

• x = 10 inches

The shapes are similar. Use proportions to find the value of x.

• x = 8 inches

• x = 13 inches

• x = 10 inches

• x = 12 inches

The shapes are similar. Use proportions to solve for y.

• y = 11 ft

• y = 4.5 ft

• y = 5 ft

• y = 6.5 ft

The shapes are similar. Use proportions to find the value of y.

• y = 30 m

• y = 25 m

• y = 10 m

• y = 32 m

The shapes are similar. What is the scale factor? Simplify your answer.

• 4:1

• 1:5

• 5:1

• 5:4

The triangles are similar. Use proportions to find the value of x.

• x = 5

• x = 1

• x = 3

• x = 4