Question

3. Find the area of quadrilateral ABCD in which
AB = 29 cm, BC = 21 cm, AC = 20 cd= 34 da= 42​

Answer 1

Answer:

since , 20,21 and 29 are triplets of pythagoras .

∆ ABC is a right angled ∆ at C .

so, ∆ABC area = 1/2*base*Height = 20*21/2 = 210cm²

now, ∆ADC,

semi - perimeter = 42+34+20/2 = 48

∆ADC area = √48*6*14*28 = √6*8*6*2*7*7*4 = 6*7*8 = 336cm²

so,

qaudralitral ABCD area = 210+336 = 546cm² (Ans)

(Mark as brainlist if you understand my solution)