Free Printable prove isosceles base angles

1.

what is almost always the first reason in a proof?

a)

given

b)

reflexive

c)

definition of bisector

d)

CPCTC

2.

Which of these is the given for this theorem?

a)

$\Delta ABC$ is isosceles with base $\overline{AB}$

b)

$\angle A\ \cong\ \angle B$

c)

draw a midpoint on $\overline{AB}$ to get two $\cong$ $\angle s$

3.

If $\overline{AB}$ is the base of the isosceles triangle $\Delta ABC$ , which two sides are congruent?

a)

$\overline{AB}\ \cong\ \overline{AC}$

b)

$\overline{AB}\ \cong\ \overline{BC}$

c)

$\overline{AC}\ \cong\ \overline{BC}$

4.

What is the reason to justify the statement $\overline{AC}\ \cong\ \overline{BC}$ ?

a)

definition of isosceles

b)

all right angles $\cong$

c)

radii of a circle $\cong$

d)

definition of midpoint

5.

We need to add an auxiliary line to divide $\Delta ABC$ into two congruent triangles. Which statement will do that?

a)

Let D be the midpoint of $\overline{AB}$

b)

Let D be the midpoint of $\overline{BC}$

c)

Let D be the midpoint of $\overline{AC}$

6.

How do we know we can draw a midpoint D on $\overline{AB}$ ? What reason will we write?

a)

every segment has a midpoint

b)

Given

7.

What are the two congruent segments formed by the midpoint D?

a)

\overline{AD}\ \cong\ \overline{BD}

b)

$\overline{AC}\ \cong\ \overline{BC}$

c)

$\overline{CD}\ \cong\ \overline{CD}$

d)

$\overline{AB}\ \cong\ \overline{CD}$

8.

What is the reason to justify the statement $\overline{AD}\ \cong\ \overline{BD}$ ?

a)

definition of isosceles

b)

all right angles $\cong$

c)

radii of a circle $\cong$

d)

definition of midpoint

9.

Which reason says that every shape is congruent to itself?

a)

transitive property

b)

reflexive property

c)

symmetric property

d)

equilateral property

10.

Which of these reflexive property statements is worth including because the shape is in both triangles?

a)

$\overline{DA}\ \cong\ \overline{DA}$

b)

$\overline{BC}\ \cong\ \overline{BC}$

c)

$\overline{AB}\ \cong\ \overline{AB}$

d)

$\overline{CD}\ \cong\ \overline{CD}$

11.

Which of the following is a correct triangle congruence statement?

a)

$\Delta DBC\ \cong\ \Delta DAC$

b)

$\Delta BCA\ \cong\Delta ADC$

c)

$\Delta ACD\ \cong\ \Delta DBC$

d)

$\Delta CBD\ \cong\ \Delta ACD$

12.

Why is $\Delta ACD\ \cong\ \Delta BDC$ ?

a)

SSS

b)

SAS

c)

ASA

d)

AAS

13.

Which of the following must be true because $\Delta DBA\ \cong\ \Delta DCA$ ?

a)

$\angle CAD\ \cong\ \angle CBD$

b)

$\angle ACD\ \cong\ \angle BCD$

c)

$\angle CDA\cong\ \angle CDB$

d)

$\angle ACB\ \cong\ \angle DAC$

14.

What is CPCTC an abbreviation for?

a)

Corresponding Parts of Congruent Triangles are Congruent

b)

Congruent Parts of Corresponding Triangles are Congruent

c)

Concurrent Perpendiculars of Corresponding Triangles are Congruent

d)

Complementary Parts of Congruent Triangles are Corresponding

15.

The last statement of every proof is what you're trying to prove. What is that in this case?

a)

$\angle CAB\ \cong\ \angle CBA$

b)

D is the midpoint of $\overline{AB}$

c)

$\Delta ADC\ \cong\ \Delta BDC$

d)

$\overline{AC}\ \cong\ \overline{BC}$

prove isosceles base angles

Total questions: 15

Worksheet time: 8mins

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