How do you find the area of an isosceles triangle if the two equal sides are 10cm and the base is 12cm?

2 Answers
Jul 22, 2015

I found: 48"cm"^2

Explanation:

Considering:
enter image source here
applying Pythagoras on half triangle you get:
h^2+6^2=10^2
h=8cm
So Area=(basexxheight)/2=(12xx8)/2=48"cm"^2

Jul 22, 2015

Area = 48 sq. cm.
color(white)("XXXX")color(white)("XXXX")(Using Heron's formula)

Explanation:

As an alternate solution method:

Heron's Formula for the area of a triangle with sides a, b, c
color(white)("XXXX")A = sqrt(s(s-a)(s-b)(s-c))
color(white)("XXXX")color(white)("XXXX")where s is the semi-perimeter (i.e. s= (a+b+c)/2

In this case:
color(white)("XXXX")s = 16

color(white)("XXXX")A = sqrt(16(6)(6)(4))
color(white)("XXXX")color(white)("XXXX")= sqrt(4^2*6^2*2^2)
color(white)("XXXX")color(white)("XXXX")=48