Q21 of 69 Page 240

The question consists of two statements namely, Assertion (a) and Reason (R). Please select the correct answer.











Assertion(A)



Reason (R)



The area of an isosceles triangle having base = 8cm and each of the equal sides = 5cm is 12cm2.



The area of an isosceles triangle having each of the equal sides as a and base =b is .


In the given question, we have

Area of isosceles triangle =


Here, we have:


a = 5 cm and b = 8 cm


∴


= 2 ×


= 2 ×


= 2 × 6


= 12 cm2


Also, Area of an isosceles triangle having each of the equal sides as a and base b =


∴ Both Assertion and Reason are true


Hence, option (a) is correct

More from this chapter

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19

For an isosceles triangle having base b and each of the equal sides as a, we have:

I. Area =


II. Perimeter = (2a +b)


III. Height =


Which of the following is true?

 20

The question consists of two statements namely, Assertion (a) and Reason (R). Please select the correct answer.











Assertion (A)



Reason (R)



Area of an equilateral triangle having each side equal to 4cm is sq cm.



Area of an equilateral triangle having each side a is a2 sq units.


 22

The question consists of two statements namely, Assertion (a) and Reason (R). Please select the correct answer.











Assertion(A)



Reason (R)



The area of an equilateral triangle having side 4cm is 3cm2



The area of an equilateral triangle having each side a is (a2) sq units.


 23

The question consists of two statements namely, Assertion (a) and Reason (R). Please select the correct answer.











Assertion (A)



Reason (R)



The sides of the triangle ABC are in the ratio 2 : 3 : 4 and its perimeter is 36 cm. Then ar(Δ ABC) = cm2.



If 2s = (a + b +c) where a, b, c are the sides of the triangle, then its area is = .