# What’s new? February 2020

2019-20: Sep | Oct | Nov | Dec | Jan

#### Responses to requests

In response to requests from several subscribers, we’ve created a new topic, G20d, with resources for trigonometry in 3D, including a GeoGebra applet.

We have also updated both applets at G17f on surface area to allow you to now demonstrate with triangular prisms and square-based pyramids, as well as cuboids as before:

We have added an applet to A4e that demonstrates the “grouping” method of factorising non-monic quadratic expressions. The solution isn’t revealed all at once; rather, the slider allows the steps to be revealed one at a time. It is therefore possible to use this applet for backwards fading in class.

A former colleague of mine asked if I could share an applet that she’d seen me use in the past. This is one I use after students are comfortable finding the area of a triangle using $$\frac{1}{2}ab\text{sin}C$$. I tweeted the following about this applet, a slightly updated version of which is available at G23a Area of a triangle using sine:

#### Vocabulary resources

We have started adding content highlighting the etymology of key words, creating cross-curricular links where possible. For example, students come across convection in science, and this originates from the same Latin word as vector:

#### TopTopics, Random Question Generators, and Skills Drills worksheets

Questions on Rounding have been added to TopTopics:

We have included quick-access sets of random question generators under the Teacher Resources for N15b and N16a.

We have also added skills drill worksheets for these topics.