Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Triangle is right-angled at
MATHEMATICS · Single correct · CBSE · Mathematics · Triangles · Triangles
Problem
Triangle
A
B
C
ABC
A
B
C
is right-angled at
C
C
C
, while triangle
D
E
F
DEF
D
E
F
is right-angled at
F
F
F
. It is known that
A
C
=
12
cm
AC = 12\,\text{cm}
A
C
=
12
cm
,
A
B
=
13
cm
AB = 13\,\text{cm}
A
B
=
13
cm
, and
D
F
=
12
cm
DF = 12\,\text{cm}
D
F
=
12
cm
. If
△
A
B
C
≅
△
D
E
F
\triangle ABC \cong \triangle DEF
△
A
B
C
≅
△
D
E
F
, the length of
D
E
DE
D
E
(in cm) is (a)
12
12
12
(b)
15
15
15
(c)
13
13
13
(d)
5
5
5
Related theory
Triangle Congruence
Triangle Congruence Criteria
Similarity
Congruence of triangles
Triangles
Browse the problem library