Question

Question #c23fd

Answer 1

Area of triangle is `73.2` sq.cm.

Explanation:

Let `l and b` be the length of legs and base of isocelles triangle

`Delta ABC ; b=l-3 ; P=b+2l=42 :. l-3+2l=42` or

`3l=45:. l=15:. b=15-3=12 ; h= 12 1/5=12.2` cm.

Area of triangle is `A_t =1/2*b*h`,where `h` is altitude.

`A_t =1/2*b*h=1/2*12*12.2=73.2` sq.cm.

Area of triangle is `73.2` sq.cm [Ans]