Basic Geometry : Plane Geometry

Study concepts, example questions & explanations for Basic Geometry

varsity tutors app store varsity tutors android store

Example Questions

Example Question #1211 : Basic Geometry

Tri 8

Given the above right triangle, find the length of the missing side.

Possible Answers:

Correct answer:

Explanation:

To find the length of the side x, we must use the Pythagorean Theorem

.  

However, this time since we are given the value of the hypotenuse, we will solve for side b rather than c.  

So, when we plug the given values into the formula, the equation looks like 

 

which can be simplified to 

.  

Next, solve for b and we get a final answer of 

.  

Example Question #221 : Triangles

Tri 9

Find the length of the missing side of the right triangle.

Possible Answers:

Correct answer:

Explanation:

To find the length of the side x, we must use the Pythagorean Theorem

.  

However, this time since we are given the value of the hypotenuse, we will solve for side b rather than c.  

So, when we plug the given values into the formula, the equation looks like 

 

which can be simplified to 

.  

Next, solve for b and we get a final answer of 

.  

Example Question #35 : Right Triangles

Tri 11

Find the length of the missing side of the right triangle. 

Possible Answers:

Correct answer:

Explanation:

To find the length of the side x, we must use the Pythagorean Theorem

.  

However, this time since we are given the value of the hypotenuse, we will solve for side b rather than c.  

So, when we plug the given values into the formula, the equation looks like 

 

which can be simplified to 

.  

Next, solve for b and we get a final answer of 

.  

Example Question #21 : How To Find The Length Of The Side Of A Right Triangle

The three sides of a triangle have lengths  , and .

True or false: the triangle is a right triangle.

Possible Answers:

True

False

Correct answer:

False

Explanation:

We can rewrite each of these fractional lengths in terms of their least common denominator, which is , as follows:

By the Pythagorean Theorem and its converse, a triangle is right if and only if

,

where  is the length of the longest side and  and  are the lengths of the other two sides. 

Therefore, we can set , and test the truth of the statement:

The statement is false, so the Pythagorean relationship does not hold. The triangle is not right.

Example Question #1211 : Plane Geometry

The three sides of a triangle have lengths 0.8, 1.2, and 1.5. 

True or false: the triangle is a right triangle.

Possible Answers:

False

True

Correct answer:

False

Explanation:

By the Pythagorean Theorem and its converse, a triangle is right if and only if

,

where  is the length of the longest side and  and  are the lengths of the other two sides.

Therefore, set  and test the statement for truth or falsity:

The statement is false, so the Pythagorean relationship does not hold. The triangle is not right.

 

Example Question #38 : Right Triangles

The three sides of a triangle have lengths , and .

True or false: the triangle is a right triangle.

Possible Answers:

False

True

Correct answer:

True

Explanation:

By the Pythagorean Theorem and its converse, a triangle is right if and only if

,

where  is the length of the longest side and  and  are the lengths of the other two sides. 

Therefore, we can set , and test the truth of the statement:

The statement is true, so the Pythagorean relationship holds. The triangle is right.

Example Question #39 : Right Triangles

Shape area right triangle

In the right triangle shown here,  and . What is the length of the base ?

Possible Answers:

Correct answer:

Explanation:

Given the lengths of two sides of a right triangle, it is always possible to calculate the length of the third side using the Pythagorean Theorem:

Here, the given side lengths are  and . Solving for  yields:

.

Hence, the length of the base  of the given right triangle is  units.

Example Question #23 : How To Find The Length Of The Side Of A Right Triangle

Given:  and .

 is an acute angle;  is a right angle.

Which is a true statement?

Possible Answers:

Correct answer:

Explanation:

 and . However, the included angle of  and , is acute, so its measure is less than that of , which is right. This sets up the conditions of the SAS Inequality Theorem (or Hinge Theorem); the side of lesser length is opposite the angle of lesser measure. Consequently, .

Example Question #14 : Triangles

Trig_id

If  and , how long is side ?

Possible Answers:

Not enough information to solve

Correct answer:

Explanation:

This problem is solved using the Pythagorean theorem  .  In this formula  and  are the legs of the right triangle while  is the hypotenuse.

Using the labels of our triangle we have:

 

 

Example Question #1 : How To Find The Length Of The Hypotenuse Of A Right Triangle : Pythagorean Theorem

If one of the short sides of a 45-45-90 triangle equals 5, how long is the hypotenuse?

Possible Answers:

√10

5

√15

5√2

π

Correct answer:

5√2

Explanation:

Using the Pythagorean theorem, x2 + y2 = h2. And since it is a 45-45-90 triangle the two short sides are equal. Therefore 52 + 52 = h2 .  Multiplied out 25 + 25 = h2.

Therefore h2 = 50, so h = √50 = √2 * √25 or 5√2.

Learning Tools by Varsity Tutors