All ISEE Upper Level Math Resources
Example Questions
Example Question #3 : How To Find An Angle In Other Polygons
The measures of the angles of an octagon form an arithmetic sequence. The greatest of the eight degree measures is . What is the least of the eight degree measures?
This octagon cannot exist.
The total of the degree measures of any eight-sided polygon is
.
In an arithmetic sequence, the terms are separated by a common difference, which we will call . Since the greatest of the degree measures is , the measures of the angles are
Their sum is
The least of the angle measures is
The correct choice is .
Example Question #4 : How To Find An Angle In Other Polygons
What is of the total number of degrees in a 9-sided polygon?
The sum of the angles in a polygon can be found using the equation below, in which t is equal to the total sum of the angles, and n is equal to the number of sides.
Therefore, the equation for the sum of the angles in a 9 sided polygon would be:
Therefore, of the total sum of degrees in a 9 sided polygon would be equal to 180 degrees.
Example Question #21 : Geometry
The measures of the angles of a nine-sided polygon, or nonagon, form an arithmetic sequence. The least of the nine degree measures is . What is the greatest of the nine degree measures?
The total of the degree measures of any nine-sided polygon is
.
In an arithmetic sequence, the terms are separated by a common difference, which we will call . Since the least of the degree measures is , the measures of the angles are
Their sum is
The greatest of the angle measures, in degrees, is
is the correct choice.
Example Question #11 : How To Find An Angle In Other Polygons
The measures of the angles of a ten-sided polygon, or decagon, form an arithmetic sequence. The least of the ten degree measures is . What is the greatest of the ten degree measures?
This polygon cannot exist.
This polygon cannot exist.
The total of the degree measures of any ten-sided polygon is
.
In an arithmetic sequence, the terms are separated by a common difference, which we will call . Since the least of the degree measures is , the measures of the angles are
Their sum is
The greatest of the angle measures is
However, an angle measure cannot exceed . The correct choice is that this polygon cannot exist.
Example Question #21 : Geometry
The seven-sided polygon - or heptagon - in the above diagram is regular. What is the measure of ?
In the diagram below, some other angles have been numbered for the sake of convenience.
An interior angle of a regular heptagon has measure
.
This is the measure of .
As a result of the Isosceles Triangle Theorem, , so
.
This is also the measure of .
By angle addition,
Again, as a result of the Isosceles Triangle Theorem, , so
Example Question #11 : How To Find An Angle In Other Polygons
What is the sum of all the interior angles of a decagon (a polygon with ten sides)?
The sum of the angles in a polygon can be found using the equation below, in which t is equal to the total sum of the angles, and n is equal to the number of sides.
Example Question #12 : Other Polygons
If each angle in a pentagon is equal to , what is the value of ?
The sum of the angles in a polygon can be found using the equation below, in which t is equal to the total sum of the angles, and n is equal to the number of sides.
Given that a hexagon has 6 angles, the total number of angles will be:
To find the value of each angle, we divide 540 by 5. This results in 108 degrees.
Thus,
Example Question #25 : Plane Geometry
What is the value of an angle (to the nearest degree) in a polygon with sides if all the angles are equal to one another?
The sum of the angles in a polygon can be found using the equation below, in which t is equal to the total sum of the angles, and n is equal to the number of sides.
Given that a hexagon has 6 angles, the total number of angles will be:
Given that there are 3,600 degrees total in a polygon with 22 sides, the number of degrees in each angle can be found by dividing 3,600 by 22. To the nearest degree, this results in 164 degrees. Therefore, 164 is the correct answer.
Example Question #1 : How To Find The Length Of A Side In Other Polygons
The perimeter of a regular octagon is one mile. Give the sidelength in feet.
One mile is equal to 5,280 feet, so divide this by 8:
feet
Example Question #2 : How To Find The Length Of A Side In Other Polygons
What is the sidelength, in feet and inches, of a regular octagon with perimeter feet?
feet is equivalent to inches. Each side of a regular octagon, an eight-sided figure, measures one-eighth of this:
Each side of an octagon with perimeter feet measures
inches.
Since
,
this is equal to .