Triangle Classification
Exterior Angle Theorem
Medians, Perpendicular Bisectors & Altitudes
Triangle Inequality Theorem
Unit 1 Spiral
100
Classify the Triangle Shown
What is a ...
Scalene Obtuse Triangle
100
What is the value of x?
What is 117?
72+45= x
100
In Triangle ABC , AD is an altitude on BC. Draw an appropriate diagram.
100
Can side lengths of 4 cm, 7 cm, and 12 cm form a triangle? Explain.
What is...
No because we check if 4+7 >12
and 11 is not > 12.
100
Given the diagram shown of two parallel lines cut by a transversal, what is the relationship between A & B?
What is A = B, because A and B are corresponding angles
200
Classify the Triangle Shown
What is an Isosceles Obtuse Triangle?
200
What is the value of x?
What is 110?
180-40= 140 , 140/2 =70
Both base angles = 70
70+40= 110 or 180-70 = 110
200
In Triangle ABC, BD is a median.
Form a congruence statemet. (ex. ____ = _____)
What is AD = DC?
200
Two sides of a triangle measure 6 cm and 10 cm. Which could be the length of the third side?
A. 4 cm
B. 8 cm
C. 16 cm
D. 18 cm
What is 8?
6+10=16
10-6=4
Number must be between 4 and 16 not equal to...
200
If AE is perpendicular to ED solve for x.
What is x = 15?
(2x+5)+(3x-10)+(x+5)=90
300
Classify a triangle that has interior angles measures of:
(3x+10)
(4x+10)
(8x+10)
What is a Right Triangle?
(3x+10)+(4x+10)+(8x+10)=180
x= 10
Angles = 40, 50 and 90
300
In DEF, an exterior angle at F is represented by 8x + 15. If the two non-adjacent interior angles are represented by 4x + 5, and 3x + 20, find the value of x
What is x= 10?
(3x+15)+(4x+5)=8x+15
300
In Triangle ABC, CD is a perpendicular bisector. If <A= 44, what is the measure of < DCA?
What is 46 degrees?
300
Which side is the longest?
What is AB?
<B= 65
so <C is largest angle and AB is the side across, and the largest side is always across from the largest angle.
300
Given the diagram of two parallel lines cut by a transversal, solve for x
What is x = 24?
Same side interior angles
(3x+40)+(2x+20)=180
400
What is the classification of a triangle that has a perimeter of 51 cm. Its side lengths are:
(2x+3)
(3x-4)
(x+10)
What is an equilateral triangle?
(2x+3)+(3x-4)+(x+10)=51
x= 7
Each side = 17
400
The measure of an exterior angle at C of an isosceles triangle ΔABC is 130 degrees. If AC = BC, find the measure of each angle of the triangle.
What is <A & <B= 65, <C=50
130/2 =65
400
In triangle JOE, Medians ME, TO and JA intersect at point P. If JP = 14, what is the value of JA?
What is 21?
Centriod--> 2:1 ratio
JP->2 PA->1
JP=14 --> PA = 7 , JA= 14+7
400
Triangle (MAT) has a perimeter of 60 cm. Its side lengths are:
(MA=3x-2)
(AT=2x+4)
(MT=x+10)
Find (x) and all three side lengths. Then determine the largest angle and justify your answer.
What is <Tis the largest angle because it is opposite the longest side, MA.
(3x-2)+(2x+4)+(x+10)=60
x=8
MA=22, AT=20, and MT=18 cm.
<Tis the largest angle because it is opposite the longest side, MA.
400
Given that GI = IH , If m∠EGB = 70° and m∠DIG =140°, explain why AB||CD.
1)<IGH = IHG because base angles of isosceles triangle are =.
2) <DIG = 140 so <IGH and <IHG = 70 each (exterior angle theorem)
Answer: Yes AB || CD because <EGB = <GHI and they are in corresponding angle positions. Since parallel line rule of corresponding angles applies, lines must parallel.
500
Given the diagram, Classify the triangle shown.
What is an isosceles Triangle.
Base angles are congruent so sides across are equal... 4x+15 = 6x - 5
x=10
AB= 55, AC= 55 , BC = 40 .
2 sides are equal so isoscles.
500
In triangle MAT, line AT is Extended to point H to form an exterieor angle. Find the measure of the exterior angle if...
<M=(3x+5)
<A=(4x+15)
<MTH=(10x-10)
What is <MTH = 90 ?
(3x+5)+(4x+15)=(10x-10)
500
In triangle JOE, Medians ME, TO and JA intersect at point P. JO = 22, OP=4 and JE = 18. What is the perimeter of Triangle JOT?
What is 37?
OP = 4 so PT=2
JE= 18 so JT= 9
Perimeter = JO+OT+JT
22+6+9= 37
500
What is the shortest side of Triangle ADC?
What is DC?
<D= 35+75 = 110(exterior angle theorem)
<CAD= 180-(110+40)= 30 (interior <'s add to 180)
500
In the diagram below, 
, and 
and 
are draw. If <AEG= 110 and <DGF= 60 what is the measure of <EGF?
What is 50?
CGE = 70 (AEG and CGE are same side interior =180)
then Linear pairs (CGE +EGF +DGF= 180)
70+x+60=180 , x=50