Solution,
Given:
In ΔMNO,
MN (a) = 24 cm
NO (b) = 25 cm
MO (c) = 7 cm
To find,
Area of triangle ΔMNO,
Here,
Semi-Perimeter (s) \(=\frac{a+b+c}2\)
\(=\frac{24cm+25cm+7cm}2\)
\(=\frac{56cm}2\)
=28cm
Now using formula,
Area of triangle (A) = \(\sqrt{s(s-a)(s-b)(s-c)}\)
= \(\sqrt{28(28-24)(28-25)(28-7)}cm^2\)
= \(\sqrt{28x4x3x21}cm^2\)
=\(\sqrt{7056}cm^2\)
=\(84cm^2\)
∴ Area of triangle MNO is 84 cm2.