Question

triangleABC is an isoceles right angled triangle in which angle a equals 90 degree. calculateB​

Answer 1

Answer:

if angle A is 90 then B=C according to isosceles triangle theorem ,angle opposite to congruent sides are equal

sum of all angles  of triangle=180

i.e A+B+C=180

90+B+C=180

B+C=90

i.e 2B=90

I.E B=45 and C=45

PLEASE MARK AS BRAINLIEST

Step-by-step explanation:

Answer 2

Answer:

The value of angle B will be 45 degrees

Step-by-step explanation:

Isosceles triangle is the triangle in which two sides are equal. This condition results the triangle holds two equal angle( angle made by each of those equal side and the third unequal side)

Now in our question it is given that angle A = 90 degrees

now if we consider it one of those equal angles then the other equal angle will be 90 degrees. But a Triangle hold total of 180 degrees ( summation of three angles) . But here we are getting 180 degrees by adding two equal angles only. So it can not be possible. Which means we can not consider the 90 degree angle is one of those equal angle. So this 90 degree angle is actually the third unequal angle.

Now say two equal angles will be angle B and angle C

therefore we can write

∠A + ∠B + ∠C = 180

or 90 + ∠B + ∠B = 180   [ since ∠B = ∠C ]

or 2∠B = 180 - 90

or 2∠B = 90

or ∠B = 45 degrees

(Answer)