Q23 of 168 Page 4

In a quadrilateral ABCD, , , prove that .

We have


∠B=90 and


AD2=AB2+BC2+CD2 (Given)


But AB2+BC2=AC2


AD2=AC2+CD2


By converse of by Pythagoras


∠ACD=90


More from this chapter

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21

In , is obtuse, and . Prove that:

(i)


(ii)

22

In a right right-angled at C, if D is the mid-point of BC, prove that .

 24

In an equilateral, , prove that .

 25

is a right triangle right-angled at A and . Show that

(i) (ii)


(iii) (iv)