Intermediate November 2021 Unit 1 Q10
10. The sizes of angles \(a\) and \(b\) in the triangle shown below are in the ratio 2 : 3.
Diagram not drawn to scale
Calculate the size of each of the angles \(a\) and \(b\).
You must show all your working. [3]
\(a\) = ………………… ° \(b\) = ………………… °
| Scheme | Marks | Comments |
|---|---|---|
| (a + b = 180 – 25) = 155 | B1 | B1 for sight of 155 |
| (a =) \(\dfrac{155}{5}\) × 2 OR (b =) \(\dfrac{155}{5}\) × 3 or equivalent | M1 | FT ‘their stated 155’. |
| a = 62(°) AND b = 93(°) | A1 | Allow M1A0 if the angles are reversed and not corrected. |