Preview Grade 3:
MG 1.3 Find the perimeter of a polygon with integer sides.
UNDERLYING SKILLS AND CONCEPTS:
measuring to the nearest inch;
addition
Perimeter
a
K
ey Ide
The perimeter of a figure is the distance around a figure.
You can find the perimeter by measuring the length of
each side and then adding the lengths.
E x am p l E
B – © CSL Associates, Inc. All rights reserved.
Use an inch ruler. What is the perimeter of the triangle?
Perimeter 3 4 5 12 inches
Chapter 24 – Lesson 3
page 283
Name
P RAC T I C E
Use an inch ruler. Find each perimeter.
1
2
inches
about 10
inches
3
about 8
Math
Reasoning
4
inches
Perimeter
MR 2.0
Which has a greater perimeter? A triangle that has all sides 3
inches long or a square that has all sides 2 inches long. Explain.
The triangle. Its perimeter is 9 inches and the
perimeter of the square is 8 inches.
page 284
Chapter 24 – Lesson 3
B – © CSL Associates, Inc. All rights reserved.
about 8
Name
P RAC T I C E
Use an inch ruler. Find each perimeter.
1
2
about 6
inches
about 4
inches
Math
Reasoning
4
about 12
inches
Perimeter
MR 2.0
Which has a greater perimeter? A triangle that has all sides 2
inches long or a square that has all sides 3 inches long. Explain.
The square. It’s perimeter is 12 inches and the
perimeter of the triangle is 6 inches.
page 190
Home Resource and Homework
Chapter 24 Lesson 3
B – © CSL Associates, Inc. All rights reserved.
3
MCX94TEG2Ch01_30.v9.4.1 2/19/01 19:52 Page 521
Name
P RAC T I C E
Use an inch ruler. Find each perimeter.
1
2
about 8
inches
B – © CSL Associates, Inc. All rights reserved.
about 10
inches
3
about 8
Math
Reasoning
4
inches
Perimeter
MR 2.0
Which has a greater perimeter? A triangle that has all sides 3
inches long or a square that has all sides 2 inches long. Explain.
The triangle. Its perimeter is 9 inches and the
perimeter of the square is 8 inches.
Chapter 24 – Lesson 3
Student Book Page
page 284
Name
P RAC T I C E
Use an inch ruler. Find each perimeter.
1
2
about 6
inches
about 4
inches
Math
Reasoning
4
about 12
inches
Perimeter
MR 2.0
Which has a greater perimeter? A triangle that has all sides 2
inches long or a square that has all sides 3 inches long. Explain.
The square. It’s perimeter is 12 inches and the
perimeter of the triangle is 6 inches.
page 190
Home Resource and Homework
Chapter 24 Lesson 3
B – © CSL Associates, Inc. All rights reserved.
3