In a classroom in Okigwe, Nigeria, a white dry-erase board is affixed to a yellow wall

In a classroom in Okigwe, Nigeria, a white dry-erase board is affixed to a yellow wall. A person, viewed from behind, with dark braided hair and wearing a patterned shirt, uses a black marker in their right hand to write on the lower right portion of the board. The whiteboard prominently displays a hand-drawn electronic circuit diagram labeled "Common Base (CB) amplifier," which includes an NPN transistor, resistors, capacitors, voltage sources, and input/output waveforms. Accompanying text on the board mentions "Voltage Gain of a CB Amplifier" and "Input Resistance is given," alongside acronyms such as "PNN, NNP, PPN, NPO." The heads of at least two other individuals are partially visible in the foreground, suggesting an audience within the instructional setting.