All ISEE Upper Level Quantitative Resources
Example Questions
Example Question #1 : Equilateral Triangles
is an equilateral triangle. Points are the midpoints of , respectively. is constructed.
Which is the greater quantity?
(a) The perimeter of
(b) Twice the perimeter of
(b) is greater.
It is impossible to tell from the information given.
(a) is greater.
(a) and (b) are equal.
(a) and (b) are equal.
If segments are constructed in which the endpoints form the midpoints of the sides of a triangle, then each of the sides of the smaller triangle is half as long as the side of the larger triangle that it does not touch. Therefore:
The perimeter of is:
,
which is twice the perimeter of .
Note that the fact that the triangle is equilateral is irrelevant.
Example Question #1 : Equilateral Triangles
Column A Column B
The perimeter The perimeter
of a square with of an equilateral
sides of 4 cm. triangle with a side
of 9 cm.
The quantity in Column B is greater.
The quantity in Column A is greater.
The quantities in both columns are equal.
There is not enough info to determine a relationship between the columns.
The quantity in Column B is greater.
Perimeter involves adding up all of the sides of the shape. Therefore, the square's perimeter is or 16. An equialteral shape means that all of the sides are equal. Therefore, the perimeter of the triangle is or 27. Therefore, Column B is greater.
Example Question #1 : How To Find The Area Of An Equilateral Triangle
is an equilateral triangle. Points are the midpoints of , respectively. is constructed.
Which is the greater quantity?
(a) The area of
(b) Twice the area of
(b) is greater.
(a) and (b) are equal.
It is impossible to tell from the information given.
(a) is greater.
(a) is greater.
If segments are constructed in which the endpoints form the midpoints of the sides of a triangle, then four triangles, congruent to each other and similar to the larger triangle, are formed. Therefore, one of these triangles - specifically, - would have one-fourth the area of . This means has more than twice the area of .
Note that the fact that the triangle is equilateral is irrelevant.
Example Question #2 : Equilateral Triangles
Which of the following could be the three sidelengths of an equilateral triangle?
By definition, an equilateral triangle has three sides of equal length. We can identify the equilateral triangle by converting the given sidelengths to the same units and comparing them.
We can eliminate the following by showing that at least two sidelengths differ.
2 yards = feet.
Two sides have lengths 6 feet and 7 feet, so we can eliminate this choice.
4 feet = inches
Two sides have lengths 48 inches and 50 inches, so we can eliminate this choice.
5 feet = inches
Two sides have lengths 48 inches and 60 inches, so we can eliminate this choice.
yards = feet
Two sides have lengths 4 feet and 5 feet, so we can eliminate this choice.
yards = feet = inches
All three sides have the same length, making this the triangle equilateral. This choice is correct.