Download Triangles and Their Angles

Classify each triangle as acute, equiøngulør, obtuse, or ríght'
L.K
5.w
6.
Classify each triangle as equiløteral, isosceles., or sealene.
c
7. Find the measure of each side of equilateral A/3S? with RS = ?.x * 2, ST
andTB:5x -
:
3x,
4.
8. Find the measure of each side of isosceles AABC with -AB
BC : 3y * 2, andÁC : 3J,.
9. Find the measure of each side of LABC with vertices
Classify the triangie.
A(-
:
BC if AB
:
4y.
1, 5), .8(6, l-), and C(2,
-6).
Find the m.easures of the sides of A,RS? and classify each triangle by its sides'
,.:l
18. -R(0, 2),
S(2,5), T(4,2)
R(L,3),
,S(4, 7), T(5, 4)
L4,
t
Name
Date
Class
Proctice
Form G
Porollel Lines ond Triongles
Find
mLI.
1.
Algebra Find the value of each variable.
7. Use the diagram at the right to answer the questions.
a. Which angle is an exterior angle?
b. What are its remote interior angles?
c. Find mLl andmLZ.
ilr.,
i+L"
"'
Find the value of the variables and the measures of the angles.
8.
(8x
9.
+ 2)'
(2x
+
6)"
(2x
- 6)
10. In the figure at the right, ED L CB and
ED bisects LCDB. Find m LDBA.
11. Reasoning What is the measu¡e of each angle in an isosceles right
triangle? Explain,
12. The ratio of the angle measures of the acute angles in a right triangle is 2 : 3.
Find the measures of the acute angles.
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. Teaching Resources
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43
Name
Class
PrOCtiCe
Date
(conrinued)
Form K
Porollel Lines ond Triongles
12. A tabletop easel has different angle settings.
If mLI 75 and mLZ 40, what is mL4?
:
:
Algebra use the given information to find the unknown angle measures in
the triangle.
13. The ratio of the angle measures of the acute angles in a right triangle is
I
: 3.
14. The measure of one angle of a triangle is 61. The other two angles are in a
ratioof2:S.
I 5. The measure of the exterior angle of a triangle is I 10. The measu¡es of its
remote interior angles are in a ratio of 2 : 3.
16. Think
About a Plan The measure of an exterior angle of LDEF is 4x. The
,rneasure of one of this angle's remote interior angles is x * 23.Themeasure
of the other remote interior angle is 2x * I2.Find the value of the measure
¿
of each angle of the triangle, and the measure of the exterior angle.
.
How can d¡awing
.
How are the exterior angle and the third angle of the tiangle reiated?
a
picture help you find the answers?
Find the values of the variables and the measures of the angles.
17.
18.
(4x
-
Prentice Hall Foundations Geometry
Copyright
(x
1)'
@
.
TeachÍng Resources
by Pearson Education, lnc., or its affiliates. All Rights Reserved.
46
+ 2)'
Date
Name
PRACTICE
For use efter Lesson 5.1 (pP. lzFI32)
lsosceles and Equilateral Triangles
Find each angle
measuFe or segment lengflt"
mZLFC = ?5o.
=
nZTLF =
CT=
2.î Lfr,úrd
AWW is an equilateral riangle'
nICFT
CF=
nZWN
=
mÆWT =
WV=
=WT=
SIY =
.Tl/ =
3. Complete cach statemenl
/4 is
b. An angle congnrentto Zl is
a. An angle congn:¿ntto
c. A¡
anglc congnrenlto 29 is
d.If ED =
õ
o
t)
tt
â.
@
5 and
BE = 5, then
BD=
and
,CD=
ríangle.
ABDE is an
Thue or false? Vl/rite T or
F.
4. Evay eguilateral triangle is an equiangular triangle'
5. Every isosceles tiangle is an equiangular rriangle'
6. 'Iheline of symmetfy for an isosceles triangle divides the triangle
. in¡o two right uianglcs.
(
7. If two angles of a triangle 8re co4gn¡ent, the triangle may bc
scalenc.
c¡{ÀP'rER
5
29