Answer: B: 45º
Step-by-step explanation:
A triangle is a plane figure that has 3 sides and also 3 angles.
The sum of all of the angles of triangle always 180°.
There are several types of triangles such as :
Equilateral Triangle → 3 equal sides
Isosceles Triangle → 2 equal sides
Scalene Triangle → no equal sides
If triangle ABC is an isosceles right triangle , then one of the angles will be 90°. The other two angles ( base angles ) will have the same value.
We could draw this triangle as shown in the attachment.
Let: the base angle = x
x + x + 90º = 180º
2x + 90º = 180º
2x = 180º + 90º
x = 90º ÷ 2 (90 ÷ 2)
x = 45º
