Area Problems The perimeter of an equilateral triangle is 90 cm. Find its area. 135?3 sq cm 151?3 sq cm 225?3 sq cm 250?3 sq cm 135?3 sq cm 151?3 sq cm 225?3 sq cm 250?3 sq cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Given that, perimeter = 90 cm? 3a = 90 cm [a = side]? a = 90/3 = 30 cm? Area = ?3a2 / 4 = ?3/4 x (30)2= 900 x ?3/4 = 225?3 sq cm
Area Problems The area of an equilateral triangle is ? 243 /4 sq cm. Find the length of its side. 3?3 cm 3 cm 9 cm ?3 cm 3?3 cm 3 cm 9 cm ?3 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP According to the question,area = ?3a2/4 = ?243 /4? a2 = ?81 x 3/?3 ? a = ?9 = 3 cm
Area Problems The diagonals of a squares is 4?2 cm. The diagonal of another square whose area is double that of the first square is 8?2 cm 6 cm 4?2 cm 8 cm 8?2 cm 6 cm 4?2 cm 8 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Diagonal of square = ?2a [a = side]4?2 = ?2 a a = 4 cmNow, area of square = a2 = (42) = 16Side of a square whose area is 2 x 16.a12 = 32 ? a1 = ?32 ?a14?2Now, diagonal of new square = ?2a = ?2x 4 ?2 = 8 cm
Area Problems The diagonals of two squares are in the ratio of 3 : 2. Find the ratio of their areas. 9 : 5 9 : 4 9 : 2 9 : 7 9 : 5 9 : 4 9 : 2 9 : 7 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the diagonals of the squares be 3x and 2x.? Ratio of their areas = [(1/2) (3x2)] / [(1/2) (2x2)] = 9/4
Area Problems If the sides of a squares is increased by 25%, then the area of the squares will be increased by 125% 56.25% 53.75% 50% 125% 56.25% 53.75% 50% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Required increment = 2a + [a2 / 100] %= 2 x 25 + [(252)/100)] %= 50 + (625/100)% = 56.25%
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