Question

find the area of the quadrilateral whose vertices are (1,1), (7,-3), (12,2) and (7,21)​

Answer 1

Answer:

132 sq. units..

Step-by-step explanation:

Let, A≡(1,1) , B≡(7,-3), C≡(12,2) D≡(7,21).

[FORMULA: Area of Δ= (1/2)|x₁ (y₂-y₃) + x₂ (y₃-y₁) + x₃ (y₁-y₂)| ]

First find the area of ΔABC, Let A≡(x₁,y₁), B≡(x₂,y₂) & C≡(x₃,y₃).

By putting the values in the formula-

Ar.(ΔABC) = 25sq. units.

Now, find the area of ΔADC.

So, Ar.(ΔADC) = 107 sq. units.

So, Ar.(ΔABC)+Ar.(ΔADC)= Ar.(ABCD)

⇒ Ar.(ABCD)= (107 + 25)sq. units= 132 sq. units.

Answer.

Hope it will help you.