Supply teacher deck · Drama · Year 7

Working Out Stage Lighting Angles and Props Budget for a Play

Worksheet Stimulus Worked example
Slide 1 of 7
05:00

Slide 1 of 7 · Settling starter · Drama · Year 7

5 minutes

Working Out Stage Lighting Angles and Props Budget for a Play

Stage lighting designers use geometry every day: if a lantern is tilted at the wrong angle, actors’ faces fall into shadow or the spotlight misses the trapdoor. Today you are the stage technician at Theatr y Bryn.

While the register is called: write your name, class and date on your worksheet, then look at the angle rules on the stimulus sheet and answer the starter question in rough.

Starter question: Is a 45° spotlight beam an acute, right, obtuse or reflex angle? And if two angles sit on a straight lighting bar (180°) and one is 115°, what is the other?

LNF: Numeracy → Geometry → Angle No computers needed · show all your working

Slide 2 of 7 · Today’s brief and key words · Drama · Year 7

5 minutes

Your brief: rig angles, trapdoor spotlight and £75 props grant

You will classify 6 angles on the Theatr y Bryn lighting bar, calculate missing beam angles using 180° and 360° rules, check the 45° trapdoor spotlight, and cost the props list from a £75.00 grant with a 10% school discount.

Types of angle

Acute: < 90° · Right: 90°
Obtuse: 90° to 180° · Reflex: 180° to 360°.

Angle sum rules

Straight bar = 180°.
Full turn around a clamp = 360°.
Triangle = 180°.

10% school discount

Divide the subtotal by 10, then subtract that discount from the subtotal.

DCF: Data and computational thinking → Problem-solving and modelling All diagrams and prices are on the stimulus sheet

Slide 3 of 7 · Step 1: classify the 6 rig angles · Drama · Year 7

10 minutes

Step 1: classify acute, right, obtuse and reflex angles

Look at Part A of the stimulus sheet. Classify each of the 6 lantern angles on the rig as acute, right, obtuse or reflex, and state why.

Lantern / Rig part Angle size Classification How you know
1. Fresnel wash beam spread 55° Acute It is less than 90° (between 0° and 90°).
2. Safety barn-door wide swing 135° Obtuse It is greater than 90° and less than 180°.
Step 1 on your worksheet · 10 minutes Check all 6 angles in Part A of the stimulus sheet

Slide 4 of 7 · Step 2: calculate missing beam angles · Drama · Year 7

10 minutes

Step 2: straight line (180°) and point (360°) calculations

Use the rig diagrams in Part B of the stimulus sheet. Show your subtraction clearly for missing angles a, b, c and d.

Straight overhead bar (add to 180°):
Missing angle = 180° − (known angles on the straight bar)

Full turn around a swivel clamp (add to 360°):
Missing angle = 360° − (known angles around the clamp)

Worked example (Angle a): Straight bar with 65° and 50° → 65° + 50° = 115°; a = 180° − 115° = 65°.

Step 2 on your worksheet · 10 minutes Write the full calculation for every angle

Slide 5 of 7 · Steps 3 and 4: trapdoor check & props budget · Drama · Year 7

12 minutes

Step 3 & Step 4: check the 45° trapdoor spot and £75 budget

In Step 3, check whether Lantern L4 hits the stage trapdoor at the required 45° angle. Then in Step 4, calculate the props budget from the £75.00 grant with a 10% school discount.

Step 3 (Trapdoor right-angled triangle): The vertical support post is 90° to the stage floor. If Lantern L4 is currently tilted at 128° along the straight top bar (180°), its inside angle at the top of the triangle is 180° − 128° = 52°, so the beam hits the trapdoor at 180° − (90° + 52°) = 38° (needs adjusting by 7° to reach 45°!).

Step 4 (Props budget): Add the 5 prop line totals → take off 10% school discount → subtract from £75.00.

Steps 3 and 4 on your worksheet · 12 minutes Write money with a £ sign and two decimal places

Slide 6 of 7 · Self and partner check · Drama · Year 7

5 minutes

Check your working against the success criteria

Swap sheets with a partner and check every angle and money calculation.

  • Are all 6 angles in Step 1 classified as acute, right, obtuse or reflex with a degree symbol (°)?
  • Does Step 2 show the full subtraction from 180° (for a and b) and 360° (for c and d)?
  • Does Step 3 show why a 135° exterior bar angle (giving a 45° interior angle) is needed to hit the trapdoor at 45°?
  • Does Step 4 show the £70.00 subtotal, the £7.00 (10%) discount, the £63.00 final cost and £12.00 left over?
5 minutes · partner check Try the extension task if you finish early

Slide 7 of 7 · Plenary review · Drama · Year 7

3 minutes

Quick-check answers before handing in

Check your final figures on the board before handing in your worksheet.

Task Correct answer
Step 2 missing angles a, b, c, d a = 65°, b = 48°, c = 70°, d = 130°.
Step 3 trapdoor spotlight check Current beam hits at 38°; adjust tilt by 7° (set bar angle to 135°) so beam hits at 45°.
Step 4 props budget Subtotal £70.00 − 10% discount (£7.00) = £63.00; £12.00 left from £75.00 grant.
Check your name and class are on your worksheet Hand in worksheets · stack stimulus sheets neatly