Question:
In a ∆ABC it is given that base = 12 cm and height = 5 cm. Its area is
(a) $60 \mathrm{~cm}^{2}$
(b) $30 \mathrm{~cm}^{2}$
(c) $15 \sqrt{3} \mathrm{~cm}^{2}$
(d) $45 \mathrm{~cm}^{2}$
Solution:
(b) $30 \mathrm{~cm}^{2}$
Area of triangle $=\frac{1}{2} \times$ Base $\times$ Height
Area of $\triangle A B C=\frac{1}{2} \times 12 \times 5=30 \mathrm{~cm}^{2}$