Question

Find the area of an isosceles triangle each of whose equal sides measures 13cm and whose base measures 20 cm.

Answer 1

Hey mate!!!!!

Using herons formula
$\sqrt{s(s - a)(s - b)(s - c)}$
where s is semi perimeter that is the half of perimeter
a is first side b second and c is third side.
So we have semi perimeter=
$\frac{13 + 13 + 20}{2} = \frac{46}{2} = 23$
now applying the values we have
$\sqrt{23(23 - 13)(23 - 13)(23 - 20)} \\ = \sqrt{23 \times 10 \times 10 \times 3} \\ = \sqrt{6900} = 83.066$
hope it helps dear friend ☺️✌️✌️

Answer 2

given


base = 20 cm


side measure = 13cm


we will do this by using herons formula


S = a + b +c / 2


S = 13 + 13 + 20 / 2


S = 46. /2

S = 23


S is side 23 cm


we use herons formula


√S ( S - A) ( S - B) ( S - c)


√23 ( 23 -13) ( 23 -13) ( 23 - 20)


√23 ( 10 * 10 * 3 )



√23 ( 2*5. 2*5 *3 )



10 √23 * 3


10 √69



hence you can also write the answer 10√69


or you can write the answer by simplifying the root is 83.03 cm