Question

plz help me in no 3 and 4 .

Answer 1

Q.3. solution:
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let the base of parallelogram be 'x' cm

altitude = 1/ 3 rd of base = x / 3 cm

area of parallelogram = 243 cm^2

base × altitude = 243

x × ( x/ 3) = 243

x^2 = 729 => x = √729 => x = 27 cm

Altitude = x/ 3 = 27/ 3 = 9 cm

Answer: altitude = 9 cm
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Q.4 solution:
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let two equal side be ' a, a'

let a = AB = AC = 8 cm ,

and base b = BC = 10 cm

area of isosceles triangle

= [ b ×√( 4a^2 - b^2) ] / 4

= [ 10×√(4 (8)^2 - (10)^2)]/ 4

= 10 × √156 / 4 = (5 × 2√39 )/ 2

= 5√39 cm = 5 × 6.24 = 31.2 cm^2

Answer:
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area of isosceles triangle= 31.2 cm^2