Question

Help man!
Fast!!!!!!​

Answer 1

|| ★★ FORMULA USED ★★ ||

• Area of Equaliteral ∆ = (√3/4) * (side)²
• Pythagoras Theoram..
• Area of Right angle ∆ = 1/2 * Base * Perpendicular .

|| ✰✰ ANSWER ✰✰ ||

Given that, in ∆ADC, all sides are 20cm, so we can say that, ∆ADC is a Equaliteral ∆.

So,

→ Area of ∆ADC = (√3/4) * (20)² = 5*20 * 1.73 = 173cm² .

______________

Now , in ∆ABC, we have Angle ABC is 90° and BC = 12 cm, and AC = 20cm.

So, we can say that, its a right angle ∆ .

Now, using pythagoras Theoram here , we get,

→ (12)² + AB² = (20)²

→ AB² = 400 - 144

→ AB = √(256)

→ AB = 16cm.

So, Area of right ∆ABC,

→ Area = (1/2) * 16 * 12 = 96cm² .

_______________

Now,

→ Area Quad.[ABCD] = [∆ABC] + [∆ADC]

putting both values , we get,

→ Area Quad.[ABCD] = 173 + 96 = 269cm² (b) (Ans).

Hence, Area of Quad ABCD is 269 cm².

Answer 2

$\huge\mathfrak\green{Heya!!!}$

$\huge\mathfrak\red{Answer:-}$

Traiangle ADC is an equilateral triangle because it is given that its all sides are 20cm each.

Therefore, we can say that:

Area of triangle ADC = ( root 3/4 ) × (20)^2

= 5× 20 × 1.73

= 173cm

Also, in traiangle ABC

Angie B = 90°

BC= 12cm

AC= 20cm

Using Pythagoras theorem we have,

(12)^2+ (AB)^2 = (20)^2

(AB)^2 = 400-144

(AB)^2 = 256

AB = root 256

AB = 16cm

Area of triangle ABC=

1/2 × 16× 12

=96cm^2

Area of quadrilateral ABCD= area of triangle ABC+ Area of traiangle ADC

= 173 + 96

= 269cm^2

Hence, option B is correct

$\huge\mathfrak\purple{Hope it helps!!}$