Find the angle
Triangle ABC is isosceles with AB = AC.
The angle at A is 40°.
What is the size of angle B?
An inter-species meeting on Mars
100 aliens attended an inter-species meeting on Mars. 76 of them needed breathing apparatus, 52 needed shaded goggles, but 23 aliens didn’t need either. How many aliens needed breathing apparatus goggles?
In an isosceles triangle, the base angles are equal.
ReplyDeleteSince AB = AC, the equal sides meet at A, so angles B and C are equal.
Total angles in a triangle = 180°
Angle A = 40°
So:
Angle B + Angle C = 180° - 40° = 140°
Because Angle B = Angle C:
Angle B = 140° ÷ 2 = 70°
Answer: 70°