## RS Aggarwal Class 8 Math Eighteenth Chapter Area of a Trapezium and a Polygon Exercise 18B Solution

## EXERCISE 18B

**(1) In the given figure, ABCD is a quadrilateral in which AC = 24 cm, BL ****⊥**** AC and DM ****⊥ AC such that BL = 8 cm and DM = 7 cm. Find the area of quad. ABCD.**

Solution: Area of quad. ABCD = ar (∆ADC) + ar (∆ABC)

**(2) In the given figure, ABCD is a quadrilateral – shaped field in which diagonal BD is 36 m, AL ⊥ BD and CM ⊥ BD such that AL = 19 m and CM = 11m. Find the area of the field.**

Solution: Area of the field ABCD = ar (∆ ABD) + ar (∆ BCD)

**(3) Find the area of pentagon ABCDE in which BL ⊥ AC, DM ⊥ AC and EN ⊥ AC and FP ⊥ AD such that AC = 18 cm, AM = 14 cm, AN = 6 cm, BL = 4 cm, DM = 12 cm and EN = 9 cm.**

Solution: Area of the given pentagon ABCDE

= ar (∆AEN) + ar (trap. EDMN) + ar (∆DCM) + ar (∆ACE)

**(4) Find the area of hexagon ABCDEF in which BL ⊥ AD, CM ⊥ AD, EN ⊥ AD and FP ⊥ AD such that AP = 6 cm, PL = 2 cm, LN = 8 cm, NM = 2 cm, MD = 3 cm, FP = 8 cm, EN = 12 cm, BL = 8 cm and CM = 6 cm.**

Solution: Area of hexagon ABCDEF,

= ar (∆AFP) + ar (trap. EFNP) + ar (∆DEN) + ar (∆ ABL) + ar (trap. BCLM) + ar (∆DCM)

**(5) Find the area of pentagon ABCDE in which BL ⊥ AC, CM ⊥ AD and EN ⊥ AD such that AC = 10 cm, AD = 12 cm, BL = 3 cm, CM = 7 cm and EN = 5cm.**

**(6) Find the area enclosed by the given figure ABCDEF as per dimensions given herewith.**

**(7) Find the area of given figure ABCDEFGH as per dimensions given in it.**

**(8) Find the area of regular hexagon ABCDEF in which each side measures 13 cm and whose height is 23 cm, as shown in the given figure.**