Question

48. On a circular table cover of radius 42 cm, a design is formed by a girl leaving an equilateral triangle ABC in the middle, as shown in the figure. Find the covered area of the design. [Use sqrt 3 =1.73 and pi= 22 7​

Answer 1

Answer:

area of circle = 22*42*42/7=6*22*42

area of equilateral triangle within this circle to find.

Draw a perpendicular from center O to BC be intersect BC at D. angle OCD = 30° So in the right angled triangle ODC cos30°= DC/OC => DC = 21 √3 => BC= 2*DC = 42√3cm

Now area∆ABC = √3/4 (42√3)^2

Next, area of covered portion = area of circle - area of triangle = 3255.21 square cm