Question

a perimeter of isosceles triangle is 30cm and two of its equal sides measure 12cm. find the area of triangle

Answer 1

$<b><i><u>Heya...❤$

Here's ur solution :

Let the other side be 'x'

We know that -

perimeter of Isosceles ∆

= sum of all sides.

Other two sides are 12 and 12.

Finding the value of x

$30 = 12 + 12 + x \\ 30 = 24 + x \\ x = 30 - 24 \\ x = 6cm$

Area of Isosceles ∆

$= b \div 4 \times \sqrt{4a {}^{2} - b {}^{2} }$

Finding area

$= 6 \div 4 \times \sqrt{4 \times 12 {}^{2} - 6 {}^{2} }$

calculation in the attachment.

Hence, area = 9√15 cm²

Hope it helps ✔

Answer 2

Answer:

Step-by-step explanation: perimeter of triangle ABC = 30 cm = AB + BC + CA

AB + BC + CA = 30

LET AB and BC are equal sides of the triangle

AB and BC = 12cm

12 +12+ CA = 30

CA = 6cm

Area of triangle ABC equals to √ s ( s-a)( s- b)( s- c)

s =30/ 2 =15

√ 15 ( 15 - 12 )(15-12)(15-6)

√15 ×3×3×9

√1215

=. 9√15