Formula
Area
Perimeter
Area in Irregular Figures
100
True or False - We use the area formula (A = l x w) to figure out how much space something takes up.
True
100
Find the area. Length = 10 meters, width= 4 meters
Area = 40 m2
100
What is the perimeter of the rectangle below?
38 cm.
Because 12 cm + 12 cm + 7 cm + 7 cm
or
2(12) + 2(7)
100
What is the area of the shaded figure? (Remember, the white portion also takes up space)
106 m2
Shaded portion - 120 m2
Unshaded portion - 14 m2
120 - 14 = 106
200
The find the area of a rectangle is the LENGTH x ______ ?
width
200
What is the area of a rectangle with a height of 4 feet and a length of 12 feet.
Area= 48 ft2
200
Jorge wants to build a fence around his rectangular yard. If he is going to fence the whole yard, which measures 20 yards long and 25 yards wide, how much fence will he need?
90 yards of fence
20 + 20 + 25 + 25
200
What is the area of the shaded figure? (Remember, the white portion also takes up space)
101 square meters
Shaded portion - 126 m2
Unshaded portion - 25 m2
126 - 25 = 101
300
How do you find the perimeter of a shape (object)?
Add up all the sides
300
What is the area of a square plot of land with a length of 9 yards?
Area = 81 yds2
Think about it! In a square all the sides are the same length. So if the length is 9 yards, than the width must be 9 yards.
300
The Pentagon is approximately 22 meters tall, and each of the five sides of the building is 281 meters long. If you walked the perimeter of the building, how far would you have walked?
1,405 meters
281 meters x 5 sides = 1,405
-The 22 meters is the height of the building. That information is not needed.
300
What is the area of the figure below?
24 square units
(3 x 4) + (2 x 6)
12 square units + 12 square units
400
Cleveland said to find the perimeter of a rectangle you have to use the formula, P = 2l + 2w.
Kah-riya said you have to use the formula, P = l x w.
Who is correct?
Cleveland.
Kah-riya may have confused it with the formula to solve for area, A = l x w.
400
What is the LENGTH of a rectangle that has an area of 25 yds2, and a width of 5 yards?
(do the inverse operation)
length = 5 yards
Starting with what you know,
25 yds2 = 5 yrds x length
Rewrite, 25 ÷ 5 = ?
400
What is the perimeter of the figure below? (Remember, you have to find the missing length first.)
32 cm.
Missing length (7 cm - horizontal)
10 + 6 + 3 + 3 + 3 + 7 = 32
400
What is the area of the figure below?
27 ft2
15 ft2 + 12 ft2
500
How come you can't use the formula, P = 4s, to find the perimeter for a RECTANGLE?
But, you can use both formulas, [P = 2l + 2w] and [P = 4s], to find the perimeter of a SQUARE..
Because a square is a special rectangle, but a rectangle is not a square.
OR
4 x sides means that all the sides are the same size, but in a rectangle, not all the sides are the same like in a square.
500
What is the WIDTH of a rectangle that has an area of 45 m2, and a length of 9 meters?
(do the inverse operation)
width = 5 meters
Starting with what you know, 45 m2 = 9m x width
Rewrite, 45 ÷ 9 = ?
500
What is the perimeter of the figure below? (Remember, you have to find the missing lengths first.)
36 cm.
Missing lengths (5 cm - vertical) and (6 cm -horizontal)
10 + 8 + 5 + 6 + 5 + 2 = 36
500
What is the area of the figure below? (Hint, you cannot use all those lengths)
21 ft2
15 ft2 + 6 ft2