Year 7 Maths — Understanding elementary shapes

Classify angles by size, triangles by their sides and their angles, and tell flat shapes from solid ones.

Name: ________________________

Before you start

Four angles, drawn side by side and getting wider as you go. Find out what each one is called.

Acute is under 90°, obtuse is over it, and the straight one is a half turn — 180°, which is why it stopped looking like a corner at all.

1.A triangle has sides of 5 cm, 5 cm and 8 cm. How many of its sides are equal in length?
2.An angle of 200° is which kind of angle?
- a) Acute
- b) Reflex
- c) Straight
- d) Obtuse
3.Put these kinds of angle in order by size, smallest first.
- Obtuse
- Acute
- Right
- Straight
- Reflex
4.This triangle has one right angle. Tap the corner where it is.
Write the number of the part.
5.Sort each shape by whether it is flat or solid.
Groups: Flat shape · Solid shape
- Sphere
- Triangle
- Cube
- Cylinder
- Square
- Circle
6.Match each angle to the name for its size.
- 45°
- 90°
- 120°
- 180°
- 300°
- Acute
- Straight
- Right
- Obtuse
- Reflex
7.An angle of 145° is which kind of angle?
- a) Acute
- b) Right
- c) Reflex
- d) Obtuse
8.All three angles of an equilateral triangle are equal, and they add up to 180°. How big is each one, in degrees?

1. 2
2. b) Reflex
3. 1. Acute 2. Right 3. Obtuse 4. Straight 5. Reflex
4. 2 — the bottom left corner
5. Square → Flat shape; Cube → Solid shape; Circle → Flat shape; Sphere → Solid shape; Triangle → Flat shape; Cylinder → Solid shape
6. 45° → Acute; 90° → Right; 120° → Obtuse; 180° → Straight; 300° → Reflex
7. d) Obtuse
8. 60