All ISEE Upper Level Math Resources
Example Questions
Example Question #5 : Lines
A line intersects parallel lines and . and are corresponding angles; and are same side interior angles.
Evaluate .
When a transversal such as crosses two parallel lines, two corresponding angles - angles in the same relative position to their respective lines - are congruent. Therefore,
Two same-side interior angles are supplementary - that is, their angle measures total 180 - so
We can solve this system by the substitution method as follows:
Backsolve:
, which is the correct response.
Example Question #1 : How To Find An Angle
Note: Figure NOT drawn to scale.
Refer to the above diagram. Give the measure of .
The top and bottom angles, being vertical angles - angles which share a vertex and whose union is a pair of lines - have the same measure, so
,
or, simplified,
The right and bottom angles form a linear pair, so their degree measures total 180. That is,
Substitute for :
The left and right angles, being vertical angles, have the same measure, so, since the right angle measures , this is also the measure of the left angle, .
Example Question #41 : Plane Geometry
Figure NOT drawn to scale
The above figure shows Trapezoid , with and tangent to the circle. ; evaluate .
By the Same-Side Interior Angle Theorem, since , and are supplementary - that is, their degree measures total . Therefore,
is an inscribed angle, so the arc it intercepts, , has twice its degree measure;
.
The corresponding major arc, , has as its measure
The measure of an angle formed by two tangents to a circle is equal to half the difference of those of its intercepted arcs:
Again, by the Same-Side Interior Angles Theorem, and are supplementary, so
Example Question #1 : Acute / Obtuse Isosceles Triangles
Two sides of an isosceles triangle have lengths 3 feet and 4 feet. Which of the following could be the length of the third side?
An isosceles triangle, by definition, has two sides of equal length. Having the third side measure either 3 feet or 4 feet would make the triangle meet this criterion.
3 feet is equal to inches, and 4 feet is equal to inches. We choose 36 inches, since that, but not 48 inches, is a choice.
Example Question #2 : Acute / Obtuse Isosceles Triangles
The triangles are similar. Solve for .
Because the triangles are similar, proportions can be used to solve for the length of the side:
Cross-multiply:
Example Question #661 : Grade 7
One of the base angles of an isosceles triangle is . Give the measure of the vertex angle.
The base angles of an isosceles triangle are always equal. Therefore both base angles are .
Let the measure of the third angle. Since the sum of the angles of a triangle is , we can solve accordingly:
Example Question #1 : How To Find The Length Of The Side Of A Right Triangle
A right triangle has a hypotenuse of 10 and a side of 6. What is the missing side?
To find the missing side, use the Pythagorean Theorem . Plug in (remember c is always the hypotenuse!) so that . Simplify and you get Subtract 36 from both sides so that you get Take the square root of both sides. B is 8.
Example Question #2 : How To Find The Length Of The Side Of A Right Triangle
Refer to the above diagram. Which of the following quadratic equations would yield the value of as a solution?
By the Pythagorean Theorem,
Example Question #3 : How To Find The Length Of The Side Of A Right Triangle
Note: Figure NOT drawn to scale.
Refer to the above diagram. Which of the following quadratic equations would yield the value of as a solution?
By the Pythagorean Theorem,
Example Question #4 : How To Find The Length Of The Side Of A Right Triangle
Note: Figure NOT drawn to scale.
Refer to the above diagram.
Find the length of .
First, find .
Since is an altitude of right to its hypotenuse,
by the Angle-Angle Postulate, so