Answer:
The area of parallelogram ABCD is
![78.42 \mathrm{in}^(2)](https://img.qammunity.org/2020/formulas/mathematics/high-school/gv386p2eua6wm5n48hzyyk1rhe4a6ptaol.png)
Explanation:
Given:
AD = 12 in
![m \angle C=46^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/high-school/il3fr3yn0gecdysfusag82vji21t5lqqgv.png)
![m \angle D B A=72^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/high-school/6b7xahf0zgki6kuf6a2wrqw7r7n3deaor1.png)
To Find:
The area of parallelogram ABCD=?
Solution:
When we construct the parallelogram with the given data, we get a parallelogram formed by 12 cm as one side and an angle with 46 degrees.
The area of the parallelogram can be calculated by
![a b * \sin (a n g l e)](https://img.qammunity.org/2020/formulas/mathematics/high-school/ifpfy7g7e0lzgtrm7udfcg55r2204lhhbl.png)
Substituting the value of a=12 we have
![\text { Area of parallelogram }=12 * \text { bsin } 46](https://img.qammunity.org/2020/formulas/mathematics/high-school/999euwzt7drotajx53y2wpoxwgg4jwg59l.png)
To find the value of b,
We know that area of a triangle can be expressed as,
![\text { Area of triangle }=(A b / 2) \sin (\text {angle})](https://img.qammunity.org/2020/formulas/mathematics/high-school/nk3u7zotepgceyl51jrrgdsnmjjq4a40tn.png)
So,
![(12 * B D / 2) * \sin 46=(A B * B D / 2) * \sin 72](https://img.qammunity.org/2020/formulas/mathematics/high-school/3ynoj2nd06cbn3twbwy4bza5kpr4ixa5r1.png)
Cancelling BD and 2 on both sides we get,
![12 * \sin 46=A B * \sin 72](https://img.qammunity.org/2020/formulas/mathematics/high-school/zxx9a7acczbfrf8ivyo8vz6ta4deqpxgky.png)
![A B=12 * (\sin 46)/(\sin 72)](https://img.qammunity.org/2020/formulas/mathematics/high-school/o3pe2qmosqbwyor1wia79cvlqfylbli4fs.png)
Therefore,
![b=(12 \sin 46)/(\sin 72)](https://img.qammunity.org/2020/formulas/mathematics/high-school/vbhjspjh2e4aydmm2l0s1fwurdqfwte5dy.png)
Substituting the value of b,
![=12 *\left((12 \sin 46)/(\sin 72)\right) * \sin 46](https://img.qammunity.org/2020/formulas/mathematics/high-school/y4r170kh33me9r715yi5de31srjqka0dg6.png)
=78.42
So the area of the parallelogram is
![78.42 \mathrm{in}^(2)](https://img.qammunity.org/2020/formulas/mathematics/high-school/gv386p2eua6wm5n48hzyyk1rhe4a6ptaol.png)