ABCD is a rhombus and its diagonals intersect at O.

(i) Is ΔBOC≅ΔDOC? State the condruence condition used?

(ii) Also state, if ∠BCO =∠DCO.

(i) In ΔBOC and ΔDOC

BO = DO [In a rhombus diagonals bisect each other]

CO = CO Common

BC = CD [All sides of a rhombus are equal]

ΔBOC≅ΔDOC [SSS Congurency]

(ii) ∠BCO =∠DCO from above [corresponding parts of congruent triangles]