Question

In the given figure, if l||m, then what type of a triangle is ABC ?

A. Scalene
B. Isosceles
C. Right angled
D. Both (b) and (c )

Answer 1

Correct Answer - D
Given , `l||m`,
`angleBCA=angleDEC=45^(@)` ( corresponding angles )
`angleCBA=angleEDB=45^(@)` ( corresponding angles )
`angleBCA+angleCBA+angleBAC=180^(@)`
`implies 45^(@)+45^(@)+angleBAC=180^(@)`
`implies angleBAC=90^(@)`
`:.` In `DeltaABC, angleA=90^(@), angleB=angleC=45^(@)`.
`implies DeltaABC` is a right - angled isosoceles triangle .
Hence, the correct option is (d).