Question

Find the area of an isosceles triangle whose base is 18cm and one of its equal sides is 15cm​

Answer 1

Answer:

The area of triangle - sum of all sides

so,

base- 18cm

equal side - 15cm

area of isosceles triangle - 18+15+15

48cm

area of triangle - 48cm

Answer 2

HEY MATE YOUR ANSWER IS HERE..

★ GIVEN ★

→ IN AN ISOSCELES TRIANGLE

- BASE = 18 cm

- ONE OF ITS SIMILAR SIDE = 15 cm

★ FIGURE ★

→ REFERRED TO THE ATTACHMENT

★ TO FIND ★

→ AREA OF TRIANGLE

★ CONSTRUCTION ★

→ DRAW ALTITUDE OF TRIANGLE AD

( HENCE ANGLE ADC = 90°)

( BD = DC = 9cm )

★ PROOF ★

LET THE ISOSCELES TRIANGLE BE ∆ ABC

NOW IN ∆ ABD

ANGLE ADB = 90° ( BY CONSTRUCTION )

BD = 9 cm ( BY CONSTRUCTION )

AB = 15 cm ( GIVEN )

BY PYTHAGORAS THEOREAM

AD² + BD² = AB²

AD² = 225 - 81

AD² = 144

AD = 9cm

NOW AREA OF A TRIANGLE =

1/2 × BASE × HEIGHT

= 1/2 × 18 × 12

= 9 × 12

= 108 cm²

THANKS FOR UR QUESTION HOPE IT HELPS

★ KEEP SMILING ☺️✌️ ★