Mathematics

Problem

Triangle

ABC

is right-angled at

B

with

AC = 17\text{ cm}

and

AB = 3x - 5\text{ cm}

. Triangle

DEF

is right-angled at

E

with

DF = 17\text{ cm}

and

DE = 7\text{ cm}

. If the two triangles are congruent, what is the value of

x

? a) 5 b) 4 c) 3 d) 6