Choose “Save as PDF” in the print dialog to keep a copy.

Cogito

Geometry · Chapter 4 · Lesson 3

Practice Worksheet

The Side-Splitter Theorem

A parallel cut divides both sides in the same ratio.

11 problems · about 22 minutes · G-SRT.B.4, G-CO.C.10

NameDate

Figure — use these to answer the problems

A midsegment is exactly half of the side it is parallel to.

Before: 10

After: 5

1/2 × 10 = 5

The third side10

Multiply by1

Divided by2

Figure 1

Warm Up

Straightforward practice. Get the method working first.

4 problems

Third side 16. Midsegment?
Answer
Third side 20. Midsegment?
Answer
Midsegment 6. Third side?
Answer
Cut divides 4 and 8, other side 5 and x. What is x?
Answer

Build It Up

The same ideas with more to keep track of.

3 problems

Cut divides 6 and 6, other side 9 and x. What is x?
Answer
Is a midsegment parallel to the third side? 1 for yes, 0 for no.
Answer
Third side 9. Midsegment, as a decimal?
Answer

Stretch Yourself

Mixed problems. Work out what kind of question it is before you start.

4 problems

Cut divides 2 and 10, other side 1 and x. What is x?
Answer
Does the parallel line create a similar triangle? 1 for yes, 0 for no.
Answer
The Midsegment
The third side is 14. How long is the midsegment?
Answer
The Ratio
A cut divides one side 2 and 4, the other 3 and x. What is x?
Answer