Question

Work out the missing angles. Remember that the angles in a triangle add up to 180 degrees. The angles are not drawn to scale, so do not try to measure them.

Answer 1

Answer

1. 130°
2. 140°
3. 100°
4. 70°
5. no
6. each of 60°
7. 38°
8. 90°, 45°, 45°

Step-by-step explanation:

It was calculated by angle sum property A+B+C=180°

Answer 2

1) we see that it is a right-angled triangle.

let x be the missing angle.

hence,30°+90°+x°=180°(angle sum property)

or,120°+x°=180°

or,x=180°-120°=60°

hence the missing angle of n.o 1 is 60°.

2)In n.o 2 also it is a right-angled triangle.

let x be the missing angle.

hence,50°+90°+x°=180°(angle sum property)

or,140°+x°=180°

or,x=180°-140°=40°

3)let x be the missing angle

hence,40°+40°+x°=180°(angle sum property)

or,80°+x°=180°

or,x°=180°-80°=100°

4)In n.o 2 the triangle is a right-angled triangle.

let x be the missing angle.

hence,20°+90°+x°=180°(angle sum property)

or,110°+x°=180°

or,x°=180°-110°=70°

5)let x be the missing angle as it is an isosceles triangle then the two angles of it are equal hence,

30°+x°+x°=180°(angle sum property)

or,30°+2x°=180°

or,x°=(180°-30°)÷2

or,x=150°÷2=75°

6)As we see it is an equilateral triangle hence all the angles of it are equal.

let x be the missing angle.

then,x°+x°+x°=180°(angle sum property)

or,3x=180°

or,x°=180°÷3=60°

7)In here also it is a right-angled triangle

let x be the missing angle.

hence,52°+90°+x=180°

or,142°+x°=180°

or,x°=180°-142°=32°

8)As it is an isosceles triangle two angles of it are equal.

let x be the missing angle.

hence,90°+x°+x°=180°

or,90°+2x=180°

or,x°=(180°-90°)÷2

or,x°=90°÷2=45°

Hope it helps ☺️✌️