Given alongside is a geometrical shape. C is centre of semicircle with radius BC=21 cm. △ABC is isosceles triangle. (Use π=3.14)
Which of the following statements are correct
(i) Area of triangle ABC outside circular region = 47.4075 cm²
(ii) Area of sector CBD = 276 cm²
(iii) Angle of sector CBD = 45°
(iv) Areaof∆ABC=220.5cm²
Choose the correct option from the following
(1)
Since∆ABC is isoscelesAB=BC=21 cmArea of ∆ABC:=12×AB×BC=12×(21)2=220.5 cm2∴Statement (iv) is correct.∆ABC is isosceles with∠B=90°So, the other angles each measure 45°.⇒Angle of sector CBD=45°∴Statement (iii) is correct.Area of sector CBD=θ360°×πr2=45360×3.14×21×21=173.0925 cm2∴Statement (ii) is incorrect.Area of triangle outside circular region=Area of ∆ABC-Area of sector CBD=220.5-173.0925=47.4075 cm2∴Statement (i) is correct.