All Intermediate Geometry Resources
Example Questions
Example Question #102 : Triangles
Two of the exterior angles of a triangle, taken at different vertices, measure and . Is the triangle acute, right, or obtuse?
Obtuse
Acute
Right
Right
At a given vertex, an exterior angle and an interior angle of a triangle form a linear pair, making them supplementary - that is, their measures total . The measures of two interior angles can be calculated by subtracting the exterior angle measures from :
The triangle has two interior angles of measures and . The sum of these measures is , thereby making them complementary. A triangle with two complementary acute angles is a right triangle.
Example Question #51 : Acute / Obtuse Triangles
True or false: It is possible for a triangle to have angles of measure , , and .
False
True
True
The sum of the measures of the angles of a triangle is . The sum of the three given angle measures is
.
This makes the triangle possible.
Example Question #23 : How To Find An Angle In An Acute / Obtuse Triangle
True or false: It is possible for a triangle to have three interior angles, each of whose measures are .
True
False
False
A triangle with three congruent angles is an equiangular - and equilateral - triangle; such an angle must have three angles that measure .
Example Question #111 : Triangles
Given: with perimeter 40;
True or false:
True
False
True
The perimeter of is the sum of the lengths of its sides - that is,
The perimeter is 40, so set , and solve for :
Subtract 26 from both sides:
, so by the Isosceles Triangle Theorem, their opposite angles are congruent - that is,
.
Example Question #51 : Acute / Obtuse Triangles
is an equilateral triangle; is the midpoint of ; the segment is constructed.
True or false: .
True
False
False
The referenced triangle is below:
In an equilateral triangle, the median from - the segment from to , the midpoint of the opposite side - is also the bisector of the angle , so
Each interior angle of an equilateral triangle, including , measures , so substitute and evaluate:
.
Example Question #26 : How To Find An Angle In An Acute / Obtuse Triangle
is an equilateral triangle. Locate a point along and construct . .
Evaluate .
The referenced figure is below. Note that , as is the case with all of the interior angles of an equilateral triangle.
The interior angles of an equilateral triangle each measure . An exterior angle of a triangle has as its degree measure the sum of its remote interior angles; specifically,
Substitute the known angle measures, and solve:
Example Question #1 : How To Find The Length Of The Hypotenuse Of An Acute / Obtuse Triangle
An acute scalene triangle has one side length of inches and another of inches. Find the length of the hypotenuse.
To find the length of the hypotenuse, apply the Pythagorean Theorem: , where the length of the hypotenuse.
Thus, the solution is:
Example Question #1 : How To Find The Length Of The Hypotenuse Of An Acute / Obtuse Triangle
Find the hypotenuse of the obtuse isosceles triangle shown above.
To find the length of the hypotenuse, apply the Pythagorean Theorem: , where the length of the hypotenuse.
Thus, the solution is:
Example Question #1 : How To Find The Length Of The Hypotenuse Of An Acute / Obtuse Triangle
A scalene triangle has one side length of yards and another side length of yards. Find the hypotenuse.
To find the length of the hypotenuse, apply the Pythagorean Theorem: , where the length of the hypotenuse.
Thus, the solution is:
Example Question #551 : Plane Geometry
Find the hypotenuse of the obtuse isosceles triangle shown above.
To find the length of the hypotenuse, apply the Pythagorean Theorem: , where the length of the hypotenuse.
Thus, the solution is: