The total surface area of frustum shaped glass tumbler is `(r_1 gt r_2)` `
` (a) `pi r_1 l + pi r_2 l` `
` (b) `pi l (r_1 + r_2) + pi (r_2)^2` `
` (c) `1/3 pi h ( (r_1)^2 + (r_2)^2 + r_1r_2 )` `
` (d) `sqrt (h^2 + (r_1 - r_2)^2)`

r + r_3 + r_1 - r_2 =

The total surface area of a cone of radius r/2 and length 2l , is a) 2pir(l+r) b) pir(l+r/4) c) pir(l+r) d) 2pirl

The area of the curved surface of a cone of radius 2r and slant height l/2 is a) pirl b) 2pirl c) 1/2 pir l d) pi(r+l)r

Prove the questions a(r r_(1) + r_(2)r_(3)) = b(r r_(2) + r_(3) r_(1)) = c (r r_(3) + r_(1) r_(2))

Value of 1/(r_(1)^2)'+ 1/(r_(2)^2)+ 1/(r_(3)^2)+ 1/(r_()^2) is :

Prove that (r_(1+r_2))/1=2R

The curved surface area of frustum of a cone is pi//(r_(1) +r_(2)) , where l = sqrt(h^(2) +(r_(1) + r_(2))^(2)),r_(1) and r_(2) are the radii of two ends of the frustum and h s the vertical height.

Prove that r_(1) r_(2) + r_(2) r_(3) + r_(3) r_(1) = (1)/(4) (a + b + c)^(2)

Show that 16R^(2)r r_(1) r _(2) r_(3)=a^(2) b ^(2) c ^(2)

Angle of intersection of two circle having distance between their centres d is given by : (A) cos theta = (r_1^2 + r_2^2 - d)/(2r_1^2 + r_2^2) (B) sec theta = (r_1^2 + r_2^2 + d^2)/(2r_1 r_2) (C) sec theta = (2r_1 r_2)/(r_1^2 + r_2^2 - d^2 (D) none of these