construction and bearings

ASA Triangles

• Triangles where you are given two angles and a side measurement. The side given will always be the baseline, the two angles going off it unless specified otherwise. Measure the angles with a protractor and draw a straight line along that angle on both sides of the line. Where the lines join is the top of the triangle. Use a ruler to measure the length of the lines and a protractor to measure the last angle.
• If it is already drawn for you, just measure the sides and angle.
• (Corbet Maths practice questions + Answers)
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• Caption: ASA Triangle (completed)

SAS Triangles

• Triangles where you are given two sides and an angle measurement. The sides given will always be the baseline and the left side, the angle going in between them unless specified otherwise. Measure the angle with a protractor and draw a straight line along that angle that is the same length specified. Draw a straight line in between the two lines to finish the triangle and measure the angles and the line with a ruler and protractor.
• If it is already drawn for you, just measure the side and angles.
• (Corbet Maths practice questions + Answers - same from the previous slide I think)
• 
• Caption: SAS Triangle (completed)

SSS Triangles

• Triangles where you are given three side measurements. The side already drawn will be the baseline, unless specified otherwise or not drawn at all. Pull your compass to the correct length and put the spike on the edge of the baseline on the correct side. Draw a curve from the baseline where the pencil is to about half a semi-circle. Do this for the other side as well, make sure you have the right length on your compass. Draw two lines from each side to where the curves meet. Measure the angles with a protractor.
• If it is already drawn for you, just measure the angles, but it probably won't be.
• (Corbet Maths practice questions + Answers - same from the previous slide I think)
• 
• Caption: SSS Triangle (completed)

Perpendicular and angle bisectors

• How to draw a perpendicular bisector
• Place the compass at one end of the line segment.
• Adjust the compass to slightly longer than half the line segment length.
• Draw arcs above and below the line.
• Keeping the same compass width, draw arcs from the other end of the line.
• Place ruler where the arcs cross and draw the line segment.
• How to draw an angle bisector
• Place the point of the compass on the angle, and make an arc on both lines making the angle. Then, with an arc as a center draw an arc in the middle of the angle space.