Basic Geometry : Squares

Study concepts, example questions & explanations for Basic Geometry

varsity tutors app store varsity tutors android store

Example Questions

Example Question #21 : Squares

A square has side lengths of . Find the length of the diagonal. 

Possible Answers:

Correct answer:

Explanation:

Finding the diagonal of a square is the same as finding the hypotenuse of a triangle, and uses the Pythagorean Theorem. (Imagine the square being sliced diagonally into two triangles, for you visual learners.) Within this theorem, both a and b are the same number, since the sides of a square are equal. 

Example Question #21 : Squares

Find the length of the diagonal of a square whose side length is 3.

Possible Answers:

Correct answer:

Explanation:

To find a diagonal of a square recall that the diagonal will create a triangle in the square for which it is the hypotenuse and the side lengths will be the other two lengths of the triangle.

To solve, simply use the Pythagorean Theorem to solve.

Thus,

Example Question #21 : Squares

Find the length of the diagonal of a square with side length 2.

Possible Answers:

Correct answer:

Explanation:

To solve, simply use the Pythagorean Theorem. Thus,

Remember, that when simplifying square roots, you can only pull a number out if you have two factors of it. That is why I grouped the end of this answer the way I did so you could see that since I had two squared, I could pull one out, one disappears, and the two on the outside of the parenthesis remains under the radical.

Example Question #21 : Squares

The area of a square is . What is the length of the diagonal?

Possible Answers:

Correct answer:

Explanation:

Since the area is 25 square meters and we know it's a square, the length of each side is 5 meters, since 5 x 5 = 25.

To find the length of the diagonal, use the Pythagorean theorem:

Example Question #21 : Squares

What is the length of the diagonal of a square with 3-inch sides?

Possible Answers:

Correct answer:

Explanation:

To solve, use the Pythagorean Theorem:

Example Question #22 : Squares

True or false: The length of a diagonal of a square with sides of length 1 is .

Possible Answers:

False

True

Correct answer:

False

Explanation:

A square is shown below with its diagonal.

Square 1

Each of the triangles formed is an isosceles right triangle with congruent legs - by the 45-45-90 Triangle Theorem, they are 45-45-90 triangles. Also by the 45-45-90 Triangle Theorem, the diagonal, the hypotenuse of each triangle, measures  times the length of a leg. Since each side of the square measures 1, the diagonal has length , not  .

Example Question #23 : Squares

Square

Consider the square  shown here. The length of each of its sides is  units. What is the length of its diagonal ?

Possible Answers:

Correct answer:

Explanation:

Recall that the side lengths of a square are each congruent; recall further that the angles in a square are each right angles. Hence, the diagonal  of the square  may be considered the hypotenuse of a right isosceles triangle whose other two sides are  and . The side lengths of  and  are given as  units; hence, we can deduce the diagonal  of the square  by the Pythagorean Theorem, as shown:

.

Hence, the length of the diagonal  of the square  is  units.

Example Question #27 : Squares

A square has a side length of 12 inches. What is the length of the diagonal across its face?

Possible Answers:

None of the other answers.

Correct answer:

Explanation:

Squares have four congruent sides. If one side is 12, the other sides must be as well. Since the diagonal makes a right triangle with the other sides we can use Pythagorean theorem to find the diagonal. 

Take the square root of both sides:

The length of the diagonal is 17 inches.

 

Example Question #22 : Squares

The sides of a square garden are 10 feet long. What is the area of the garden?

Possible Answers:

Correct answer:

Explanation:

The formula for the area of a square is


where  is the length of the sides. So the solution can be found by


Example Question #681 : Plane Geometry

The length of line  in the figure below is 15 inches. What is the area of the square ?

Square_diagonal

Possible Answers:

Cannot be determined

Correct answer:

Explanation:

Since  is a square, the side  is the same length as all of the other three sides.

We get area by multiplying length by width (or base by height, if you prefer), since all sides are equal, it looks like this:

Don't forget, the units are SQUARE INCHES.

Learning Tools by Varsity Tutors