All Intermediate Geometry Resources
Example Questions
Example Question #131 : Acute / Obtuse Triangles
Given: and .
True or false: From the above four statements, it follows that .
True
False
True
As we are establishing whether or not , then , , and correspond respectively to , , and .
The sum of the measures of the interior angles of a triangle is . Therefore,
Set and , and solve for :
By the Angle-Angle Similarity Postulate (AA), two triangles are similar if two angles of the first triangle are congruent to those of their counterparts in the second. and , so ; and , so . The conditions of AA are met, so it follows that . The correct response is "true".
Example Question #132 : Acute / Obtuse Triangles
Given: and .
True or false: From the above three statements, it follows that .
True
False
True
As we are establishing whether or not , then , , and correspond respectively to , , and .
Let .
Let
The measures of the interior angles of a triangle total . Therefore,
Substituting:
By the same reasoning,
Therefore, .
By the Angle-Angle Similarity Postulate (AA), two triangles are similar if two angles of the first triangle are congruent to those of their counterparts in the second. and , so the conditions of AA are met; it follows that .
Example Question #16 : How To Find If Two Acute / Obtuse Triangles Are Similar
Given: , with Point on and Point on .
True or false: From the given information, it follows that .
False
True
False
As we are establishing whether or not , then , , and correspond respectively to , , and .
If two triangles are similar, then it must hold that corresponding sides are in proportion. Specifically, if , it must hold that
By the Segment Addition Postulate,
and
Set , , , in the above proportion statement, which becomes
Reduce both ratios to lowest terms:
The corresponding sides are not proportional, so the statement is false.
Example Question #133 : Acute / Obtuse Triangles
Given: , with Point on and Point on .
True or false: From the given information, it follows that .
True
False
True
As we are establishing whether or not , then , , and correspond respectively to , , and .
By the Side-Angle-Side Similarity Theorem (SASS), two triangles are similar if two pairs of corresponding sides are in proportion and their included angles are congruent.
Examine two pairs of corresponding sides: and , and and . In both cases, their included angle is ; by the Reflexive Property of Congruence, .
It remains to be demonstrated that
By the Segment Addition Postulate,
and
Set , , , in the above proportion statement, which becomes
Reduce both ratios to lowest terms:
The corresponding sides are proportional.
The conditions of SASS have been proved, so the statement is true.
Example Question #134 : Acute / Obtuse Triangles
Given: and such that
Which statement(s) must be true?
(a)
(b)
(b) but not (a)
(a) but not (b)
(a) and (b)
Neither (a) nor (b)
(a) but not (b)
The two given angle congruences set up the conditions of the Angle-Angle Similarity Postulate - if two angles of one triangle are congruent to the two corresponding angles of another triangle, the two triangles are similar. It follows that
.
However, congruence cannot be proved, since at least one side congruence is needed to prove this. This is not given in the problem.
Therefore, statement (a) must hold, but not necessarily statement (b).
Example Question #1 : How To Find The Height Of An Acute / Obtuse Triangle
Find the height of the triangle shown above.
Use the Pythagorean Theorem to find the height of this triangle: , where the height of the triangle.
Example Question #1 : How To Find The Height Of An Acute / Obtuse Triangle
Find the height of the obtuse triangle shown above.
To solve this solution, first work backwards using the formula:
Plugging in the given values we are able to solve for the height.
Example Question #1 : How To Find The Height Of An Acute / Obtuse Triangle
Find the height of the acute triangle shown above.
To solve this solution, work backwards using the formula:
Plugging in the given values we are able to solve for the height.
Example Question #3 : How To Find The Height Of An Acute / Obtuse Triangle
A triangle has a base of and an area of square units. Find the height of the triangle.
To solve this solution, work backwards using the formula:
Plugging in the given values we are able to solve for the height.
Example Question #4 : How To Find The Height Of An Acute / Obtuse Triangle
An obtuse triangle has a base of and an area of square units. Find the height of the triangle.
To solve this solution, work backwards using the formula:
Plugging in the given values we are able to solve for the height.