Question

Find the area of the largest triangle that can be inscribed in a semicircle of radius 21 cm.

Answer 1

The largest triangle that can be inscribed in a semicircle of radius r units is 'an isosceles right triangle '
When we join the center of the semicircle to the vertex of the triangle, it becomes the altitude of that triangle which is equal to the radius of the semi-circle.

Triangle Area $=\frac{1}{2}\times base\times height=\frac{1}{2}\times 2r\times r$
$=r^2=(21{)}^2$
$=441squnits$