#### (a) In figure (i) given below, DE || BC and BD = CE. Prove that ABC is an isosceles triangle.

(b) In figure (ii) given below, AB || DE and BD || EF. Prove that DC² = CF × AC.

**Solution:**

**More Solutions:**

- DE parallel BC. If DE = 6 cm, BC = 9 cm and area of ∆ADE = 28 sq. cm
- Prove that ∆ADE and ∆ABC are similar.
- In the given figure, AB and DE are perpendicular to BC.
- In the adjoining figure, ABC is a triangle. DE is parallel to BC.
- In ∆ABC, AP: PB = 2 : 3. PO is parallel to BC and is extended to Q so that CQ is parallel to BA.
- Determine the ratio of the areas of ∆AOB and ∆COD.