All GMAT Math Resources
Example Questions
Example Question #321 : Geometry
Calculate the perimeter of an equilateral triangle whose side length is .
The perimeter of an equilateral triangle is:
Thus.
Example Question #322 : Geometry
Find the perimeter of an equilateral triangle whose side length is .
To find the perimeter, you must multiply the side length by . Thus,
Example Question #323 : Geometry
Calculate the perimeter of an equilateral triangle whose side length is .
To solve, simply multiply the side length by . Thus,
Example Question #1 : Calculating The Perimeter Of An Acute / Obtuse Triangle
A triangle has 2 sides length 5 and 12. Which of the following could be the perimeter of the triangle?
I. 20
II. 25
III. 30
II and III only.
I only
All 3 are possible.
I and II only
III only
II and III only.
For a triangle, the sum of the two shortest sides must be greater than that of the longest. We are given two sides as 5 and 12. Our third side must be greater than 7, since if it were smaller than that we would have where is the unknown side. It must also be smaller than 17 since were it larger, we would have .
Thus our perimeter will be between and . Only II and III are in this range.
Example Question #2 : Calculating The Perimeter Of An Acute / Obtuse Triangle
Triangle has sides . What is the perimeter of triangle ?
To calculate the perimeter, we simply need to add the three sides of the triangle.
Therefore, the perimeter is , which is the final answer.
Example Question #3 : Calculating The Perimeter Of An Acute / Obtuse Triangle
Triangle has height . If is the midpoint of and , what is the perimeter of triangle ?
Since BD is the height of triangle ABC, we can apply the Pythagorean Theorem to, let's say, triangle DBC and .
Since the basis of the height is at the midpoint of AC, it follows that triangle ABC, is an isoceles triangle.
We can find the perimeter by multiplying BC by 2 and add the basis of the triangle AC, which has length of .
The final answer is therefore .
Example Question #1 : Acute / Obtuse Triangles
An acute triangle has side lengths of , , and . What is the perimeter of the triangle?
For any given triangle, the perimeter is the sum of the lengths of its sides. Given side lengths of , , and , .
Example Question #4 : Calculating The Perimeter Of An Acute / Obtuse Triangle
An acute triangle has side lengths of , , and . What is the perimeter of the triangle?
For any given triangle, the perimeter is the sum of the lengths of its sides. Given side lengths of , , and , .
Example Question #3 : Acute / Obtuse Triangles
An acute triangle has side lengths of , , and . What is the perimeter of the triangle?
For any given triangle, the perimeter is the sum of the lengths of its sides. Given side lengths of , , and , .
Example Question #1 : Acute / Obtuse Triangles
Is it true that ?
Suppose you want to answer this question, and you know that and . Which of the following additional facts would help you to answer this question one way or the other?
None of these statements would be sufficient to answer the question.
If you know either that or , you have three congruencies - two sides and a nonincluded angle. This is not enough to establish triangle congruence,
If you know that , this, along with the other two statements, establishes that ; all this proves is that both triangles are isosceles.
If you also know that , however, the three statements together make three side congruencies, setting up the Side-Side-Side criterion for triangle congruence.