Given:Slant height of the conical mountain =2.5 kmArea of its base =1.54 km2Let the radius of base be 'r' km, height of the mountain in 'h' km and slant height be 'l' km Area of base =πr2⇒1.54=722​×r2 ⇒r=0.7We know that, l2=r2+h2⇒(2.5)2=(0.7)2+h2⇒6.25−0.49=h2⇒5.76=h2⇒h=2.4 Thus, the height of the mountain is 2.4 km