ΔABC is isosceles with AB = AC = 7.5 cm and BC = 9 cm (see the given figure). The height AD from A to BC, is 6 cm. Find the area of ΔABC. What will be the height from C to AB i.e., CE? - Mathematics

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Sum

ΔABC is isosceles with AB = AC = 7.5 cm and BC = 9 cm (see the given figure). The height AD from A to BC, is 6 cm. Find the area of ΔABC. What will be the height from C to AB i.e., CE?

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Solution

Area of triangle ABC = `1/2 xx "Base" xx "Height"`

= `1/2 xx BC xx AD`

= `1/2 xx 9 xx 6`

= 27 cm2

Area of triangle ABC = `1/2 xx "Base" xx "Height" = 1/2 xx AB xx CE`

`27 = 1/2 xx 7.5 xx CE`

CE = `(27 xx 2)/7.5`

CE = 7.2 cm

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Chapter 11: Perimeter and Area - Exercise 11.2 [Page 217]

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NCERT Mathematics Class 7
Chapter 11 Perimeter and Area
Exercise 11.2 | Q 8 | Page 217

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