# How do you compute the area and perimeter of a isosceles triangle with base of 11.3cm and height of 26cm?

$A = 146.9 c {m}^{2}$

$P \cong 64.5 c m$

#### Explanation:

If the base is 11.3 cm, the half base is $\frac{11.3}{2} = 5.65 c m$
(see figure below ).

Using the Pythagorean Theorem, the two other sides are:

${a}^{2} = {5.65}^{2} + {26}^{2}$

${a}^{2} = 707.9225$

$a = \sqrt{707.9225} \cong 26.6 c m$

The perimeter is:

$P \cong 11.3 + 26.6 + 26.6 \cong 64.5 c m$

The area is:

$A = \frac{11.3 \times 26}{2} = 146.9 c {m}^{2}$