find the angles
Triangle angles
vocabulary
Shapes
form a triangle
100

∠1=60°;∠2=40°;

∠3=

80°

100

有一个角为900的三角形

right angle

100


equilateral triangle

100

draw a square

100

side a 2cm 

side b 1 cm 

side c 1 cm

Can these three sides form a triangle?

No, can not.

200

在等腰三角形中

∠1=120°

∠2=

∠3=

30°

200


acute triangle

200

isosceles triangle

200

draw a circle

200

side a 4cm 

side b 6 cm 

side c 5 cm

Can these three sides form a triangle?

yes, they can.

300

∠1=53°;∠2=82°;

∠3=

45°

300


obtuse triangle

300


scalene triangle/acute triangle

300


rectangle

300

side a 7cm 

side b 3 cm 

side c 14 cm

Can these three sides form a triangle?

No, can not.

400


obtuse triangle

400


scalene triangle/obtuse triangle

400


trapezoid

400

side a 11cm 

side b 15 cm 

side c 30 cm

Can these three sides form a triangle?

No, can not.

500

side a 22cm 

side b 11 cm 

side c 35 cm

Can these three sides form a triangle?

No, they can not.