Question

plz tell this answer

Answer 1

First of all using Pythagoras Theorem, we will calculate the length of AC

AC = √(9² + 40²)

=> AC = √(81 + 1600)

=> AC = √1681

=> AC = 41


Now area of ∆ABC = 1/2 × base × height

=> Area of ∆ABC = 1/2 × 40 × 9

=> Area of ∆ABC = 20 × 9

=> Area of ∆ABC = 180m²


Now using Heron's Formula, we will calculate the area of ∆ADC

Heron's Formula =
.

s = (28 + 41 + 15)/2

=> s = 42

=> Area =
$\sqrt{42(42 - 41)(42 - 28)(42 - 15)} \\ = > \sqrt{42 \times 1 \times 14 \times 27} \\ = > \sqrt{15876} \\ = > 126$
Area = 126m²


Hence, first group cleaned more

Answer 2

first take out area of triangle ABC by 1/2×base×height....take our lenght of diagonal by pythagoras them. and then take our area of triangle CDA by herons formula ....then add area of both triangles