The base of an isosceles triangle is 12 cm and its perimeter is 38 cm. What is the area of the triangle?

1 Answer
Mar 3, 2018

Area of the isosceles triangle is #69.2# sq.cm.

Explanation:

The base of the isosceles triangle is #b=12# cm and let #l# be two

legs of the isosceles triangle. Perimeter of the isosceles triangle

is #P=b+2l or 38 = 12+2l :. 2l =38-12 or 2l=26 #or

#l=13# cm. Legs of the isosceles triangle are # 13# cm each.

Area of the isosceles triangle is #A=b/4*sqrt(4*l^2-b^2)# or

#A=12/4*sqrt(4*13^2-12^2)=3*sqrt 532 ~~ 69.2 (1dp)# sq.cm

Area of the isosceles triangle is #69.2# sq.cm. [Ans]