Question

in triangle ABC, angle A =angle C, AC =5 and BC =4. then find perimeter of triangle ABC​

Answer 1

angle A = angle C
therefore this angle is right angled triangle
angleA=angle C=45
angle B=90
by 45-45-90 therem
AB=1/underoot2×AC---(side opposite 45 angle)
AB=1/underoot 2×5
AB=5/underoot 2
AB=7.07

perimeter=AB+BC+AC
Perimeter=7.07+4+5
perimeter= 16.07

Answer 2

Given

In a triangle, ABC, angle A = angle C

AC = 15

BC =4

To find

The perimeter of triangle ABC

Solution

Given that ∠ A = ∠ C, the sides opposite to those angles are equal in measure.

That is AB = BC

Since BC =4, AB = 4

Therefore the sides of triangle become AC = 5, AB = 4, BC = 4

The perimeter of a triangle = Sum of all three sides

That is AC + BC +AB = 4 +4 +5 =13

Therefore the perimeter of the triangle ABC is 13