ACT Math : Rectangles
Study concepts, example questions & explanations for ACT Math
All ACT Math Resources
Example Questions
Example Question #372 : Geometry
What is the perimeter of a rectangle with one side of 
Based on the information provided, you know that the rectangle's area could be represented as:
Now, remember that your perimeter is just the sum of all the sides. This is:
For our data, this is:
Example Question #373 : Geometry
The area of a yard is 
Begin by computing the length of the other side of the yard. Based on the data that you have, you know that:
Now, this means that our yard's dimensions in feet are:
The perimeter will be 
Example Question #374 : Geometry
A person spends 
Based on this data, you know that the person purchased a total of 
Solve the first equation for 
Now substitute this into the first equation:
Since this is a quadratic equation, isolate everything to one side:
This is a bit tricky to factor, but it comes out as:
This means that the larger dimension is 
Example Question #1 : How To Find The Perimeter Of A Rectangle
A rectangle has an area of 
To find the length and width of a rectangle given the area and one side, simply divide the area by the given side length:
Next, to find the perimeter use the formula:
Example Question #31 : Rectangles
Find the perimeter of a perimeter with width 5 and length 8.
To solve, simply use the formula for the perimeter of a rectangle. Thus,
Example Question #32 : Rectangles
Find the perimeter of a perimeter with width 5 and length 9.
To solve, simply use the formula for the perimeter of a rectangle. Thus,
Example Question #1 : How To Find If Rectangles Are Similar
Two rectangles are similar. The perimeter of the first rectangle is 36. The perimeter of the second is 12. If the base length of the second rectangle is 4, what is the height of the first rectangle?
4
6
10
2
8
6
Solve for the height of the second rectangle.
Perimeter = 2B + 2H
12 = 2(4) + 2H
12 = 8 + 2H
4 = 2H
H = 2
If they are similar, then the base and height are proportionally equal.
B1/H1 = B2/H2
4/2 = B2/H2
2 = B2/H2
B2 = 2H2
Use perimeter equation then solve for H:
Perimeter = 2B + 2H
36 = 2 B2 + 2 H2
36 = 2 (2H2) + 2 H2
36 = 4H2 + 2 H2
36 = 6H2
H2 = 6
Example Question #382 : Geometry
Two rectangles are similar. The first rectangle has a perimeter of 
1. Create a proportion comparing the two given rectangles:
2. Solve for the length of the second rectangle by cross-multiplying:
Example Question #2 : How To Find If Rectangles Are Similar
The width of a rectangle is 5 times the length of the rectangle. The width of the rectangle is 30. What is the perimeter of the rectangle?
If the width is 5 times the length, and the width is 30, then the length is 6. The perimeter of a rectangle is 2 x width + 2 x length. 2 x 30 + 2 x 6 = 72.
Certified Tutor
All ACT Math Resources
