In an isosceles triangle, the measure of each of the equal sides is 10 cm and the angle between them is 45° . The area of the triangle is :
A. $$25 \,c{m^2}$$
B. $$\frac{{25}}{2}\sqrt 2 \,c{m^2}$$
C. $$25\sqrt 2 \,c{m^2}$$
D. $$25\sqrt 3 \,c{m^2}$$
Answer: Option C
Solution (By Examveda Team)
$$\eqalign{
& {\text{Area of the traingle :}} \cr
& = \frac{1}{2}ab\sin \theta \cr
& = \left( {\frac{1}{2} \times 10 \times 10 \times \sin {{45}^ \circ }} \right)c{m^2} \cr
& = \left( {\frac{1}{2} \times 10 \times 10 \times \frac{1}{{\sqrt 2 }}} \right)c{m^2} \cr
& = \left( {\frac{{50}}{{\sqrt 2 }} \times \frac{{\sqrt 2 }}{{\sqrt 2 }}} \right)c{m^2} \cr
& = 25\sqrt 2 \,c{m^2} \cr} $$
Why not the answer is 25√3