Question

If triangle ABC is isosceles and right angled at B, find the measure of all angles​

Answer 1

Answer:

Here B is given as 90°

A and C is unknown

An isosceles triangle has 2 sides equal so A and C are same . Let's take A and C as X

X + X + B = 180° ( sum of 3 angles of triangle is 180° )

2X + 90 = 180°

2X = 180° - 90°

2X = 90°

X = 90°/2

X = 45°

So A = 45°

B = 90°

C = 45°

Answer 2

Given

Triangle ABC is an Isosceles triangle

∠B is a right angled triangle

To Find

Measure of all angles of triangle

$\sf\huge\bold{\underline{\underline{{Solution}}}}$

Property of Isosceles triangle

In an Isosceles triangle two sides are equal and the angle opposite to the equal sides are equal.

e.g.,∆ABC is an Isosceles triangle and side AB and BC are two equal sides then ∠B=∠C=90°

and the remaining angle which is ∠A must be 90° as sum of all angles in a triangle is 180°

Therefore , ∠A=90° ; ∠B & ∠C=90°

Extra information=>

Perimeter of an Isosceles triangle=2a +b

Area of an Isosceles triangle=b× h ÷2

where b is the base and h is the height of an Isosceles triangle.