All ISEE Upper Level Math Resources
Example Questions
Example Question #41 : Triangles
Refer to the above figure. Express in terms of .
The measure of an interior angle of a triangle is equal to 180 degrees minus that of its adjacent exterior angle, so
and
.
The sum of the degree measures of the three interior angles is 180, so
Example Question #91 : Plane Geometry
In the above figure, .
Give the measure of .
and form a linear pair, so their degree measures total ; consequently,
, so by the Isosceles Triangle Theorem,
The sum of the degree measures of a triangle is , so
Example Question #10 : How To Find An Angle In An Acute / Obtuse Triangle
Figure NOT drawn to scale.
Refer to the above figure. Evaluate .
The measure of an exterior angle of a triangle, which here is , is equal to the sum of the measures of its remote interior angles, which here are and . Consequently,
and form a linear pair and, therefore,
.
Example Question #91 : Plane Geometry
Note: Figure NOT drawn to scale.
What is the measure of angle
The two angles at bottom are marked as congruent. One forms a linear pair with a angle, so it is supplementary to that angle, making its measure . Therefore, each marked angle measures .
The sum of the measures of the interior angles of a triangle is , so:
Example Question #91 : Geometry
Which of the following is true about a triangle with two angles that measure and ?
This triangle is scalene and right.
This triangle is scalene and obtuse.
This triangle cannot exist.
This triangle is isosceles and obtuse.
This triangle is isosceles and right.
This triangle cannot exist.
A triangle must have at least two acute angles; however, a triangle with angles that measure and could have at most one acute angle, an impossible situation. Therefore, this triangle is nonexistent.
Example Question #92 : Geometry
Two sides of a scalene triangle measure 4 centimeters and 7 centimeters, and their corresponding angle measures 30 degrees. Find the area of the triangle.
,
where and are the lengths of two sides and is the angle measure.
Plug in our given values:
Example Question #93 : Isee Upper Level (Grades 9 12) Mathematics Achievement
A scalene triangle has a base length and a corresponding altitude of . Give the area of the triangle in terms of .
,
where is the base and is the altitude.
Example Question #92 : Isee Upper Level (Grades 9 12) Mathematics Achievement
What is the area of a triangle on the coordinate plane with its vertices on the points ?
The base can be seen as the (vertical) line segment connecting and , which has length . The height is the pependicular distance from to the segment; since the segment is part of the -axis, this altitude is horizontal and has length equal to -coordinate .
The area of this triangle is therefore
.
Example Question #94 : Isee Upper Level (Grades 9 12) Mathematics Achievement
What is the area of a triangle on the coordinate plane with its vertices on the points ?
The base can be seen as the (horizontal) line segment connecting and , the length of which is . The height is the pependicular distance from to the segment; since the segment is part of the -axis, this altitude is vertical and has a length equal to -coordinate .
The area of this triangle is therefore
.
Example Question #53 : Triangles
Figure NOT drawn to scale.
is a right triangle with altitude . What percent of has been shaded gray?
Choose the closest answer.
The altitude of a right triangle from the vertex of its right angle - which, here, is - divides the triangle into two triangles similar to each other as well as the large triangle.
The similarity ratio of to is the ratio of the lengths of their hypotenuses. The hypotenuse of the latter is 18; that of the former, from the Pythagorean Theorem, is
The similarity ratio is therefore . The ratio of their areas is the square of this, or
The area of is
of that of , so the choice closest to the correct percent is 25%.
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