Question

24 In a quadrilateral ABCD, angle B = 90° = D. Prove that
2AC2 - BC² = AB² + AD² + DC².

25.In a triangle ABC, angle A = 90°, CA = AB and D is a point on AB produced. Prove that
DC² - BD² = 2AB X AD.

26.In an isosceles triangle ABC, AB = AC and D is a point on BC produced, Proves
AD² = AC² + BD x CD.​

Answer 1

it is prove that

${ad}^{2} = {ac}^{2} + bd \times cd$

by pythgoras theorem