Question 47A rectangle inscribed in a triangle has its base coinciding with the base $b$ of the triangle. If the altitude of the triangle is $h,$ and the altitude $x$ of the rectangle is half the base of the rectangle, then:$x=\dfrac12h$$x=\dfrac{bh}{b+h}$$x=\dfrac{bh}{2h+b}$$x=\sqrt{\dfrac{hb}{2}}$$x=\dfrac12b$