2-D shapes (age 10+)

Draw 2-D shapes using given dimensions and angles, using a ruler and protractor accurately

ages 10 to 118 practice questionsvideo included

What a learner can do afterwards

Draw a triangle with sides 5 cm, 7 cm and an included angle of 60°
Construct a rectangle with given length and width using a ruler and set square
Draw a regular pentagon given the side length and interior angle

The lesson

You already know how to measure an angle with a protractor, and you know what makes a polygon regular or irregular. Now you put both skills to work: drawing a shape so it matches exact side lengths and angles, not just roughly the right shape.

This triangle is defined by two sides and the angle between them. Once you know those three numbers, there is only one triangle that fits.

Try it together

To draw it: draw the 7 cm side first with your ruler. At one end, place your protractor on that line and mark 60°. Draw the 5 cm side from that mark. Join the two open ends, and the triangle is complete.

The same idea works for other shapes. A rectangle needs equal opposite sides and four 90° corners, checked with a set square. A regular pentagon needs equal sides and equal angles, here each one 108°, checked with a protractor at every corner.

Good to know

Keep your pencil point sharp so your ruler and protractor marks are exact. If one mark is even 1 mm or 1° off, the whole shape drifts by the time you draw the last side.

Measure carefully, mark each angle with your protractor, and draw each side to its exact length. That's how numbers become an accurate shape.

Watch it

Where it sits

Learn first

Measuring angles Regular and irregular polygons

This opens up

Measuring angles (age 11+)

Where this leads

Jobs that lean on this skill. Follow one to see everything it is built on.

Air Traffic Controller Artist Cartographer Civil Engineer Graphic Designer Interior Designer

Then practise

8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.