Question

A rectangle has length 40cm and breadth 30 cm. It
has an external isosceles triangle with equal sides of
17 cm each along one of its smaller sides as the base
of the triangle. Find the area of the pentagon thus
formed.​

Answer 1

Answer:

in this area of triangle is solved by Herons formula

and area of Pentagon= area of triangle+area of rectangle

Step-by-step explanation:

area of triangle by herons formula:

s=(a+b+c)/2

s=(17+17+30)/2

s=32

area=√s(s-a)(s-b)(s-c)

area=√32(32-17)(32-17)(32-30)

area=√32*15*15*2

area=√14400

area=120cm²

now, area of rectangle:

area= L*B

area = 40 * 30

area = 1200cm²

therefore,

area of Pentagon= area of triangle+area of rectangle

area of Pentagon=120 + 1200

area of Pentagon=1220 cm²

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