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 1. Circle Area (A) = pi r^2 Circumference (C) = 2 pi r = pi d Diameter (d) = 2 r
 2. Semi-Circle Area (A) = 1/2 pi r^2 Circumference (C) = pi r = (pi d)/2 Perimeter (P) = pi r + 2 r Diameter (d) = 2 r

 3. Regular Hexagon Perimeter (P) = 6 a Area (A) = sqrt(3)/4 xx 6 xx a^2
 4. Square Diagonal (d) = sqrt(2) a Perimeter (P) = 4a Area (A) = a^2 = d^2/2

 5. Rectangle Diagonal (d) = sqrt(l^2 + b^2) Perimeter (P) = 2(l+b) Area (A) = l b
 6. Parallelogram Area (A) = ah Perimeter (P) = 2a + 2b

 7. Rhombus Radius (r_1) = (d_1)/2 Radius (r_2) = (d_2)/2 Side (a) = sqrt(r_1^2 + r_2^2) Perimeter (P) = 4 a Area (SA) = (d_1 d_2)/2
 8. Trapezium Area (A) = h/2 (a + b) Perimeter (P) = a + b + c + d

 9. Scalene Triangle Perimeter (P) = a+b+c S = P/2 = (a+b+c)/2 Area (A) = sqrt(S (S - a) (S - b) (S - c))
 10. Rightangle Triangle Diagonal (d) = sqrt(a^2 + b^2) Perimeter (P) = a+b+c Area (A) = 1/2(a b)

 11. Equilateral Triangle Perimeter (P) = 3 a Area (A) = sqrt(3)/4 a^2
 12. Isoceles Triangle Height (h) = sqrt(a^2 - b^2/4) Perimeter (P) = 2 a + b Area (A) = (b h)/2

 13. Sector Segment Length of the arc = l = (pi r theta)/180 Area of a minor sector = (pi r^2 theta)/360 I know that for a sector & segment Radius = 10 and angle of measure = 180 . From this find out length of arc of the sector & segment. "Here "r = 10" and " theta = 180" (Given)""Length of the arc " = l = (pi r theta)/180=(22/7 * 10 * 180)/180=31.4286"Area of a minor sector "= (pi r^2 theta)/360=(22/7 * 10^2 * 180)/360=157.1429