The image contains three geometry problems, with a focus on different concepts. Let's break them down one by one:

Problem 1:

A figure is provided, which seems to involve a semicircle and a triangle. The problem asks for the following:

1. Area of the semicircle using the formula $A = \frac{1}{2}\pi r^2$, where $r$ is the radius.
2. Area of the triangle using $A = \frac{1}{2} \times \text{base} \times \text{height}$.
3. Area of the figure which involves subtracting the area of the triangle from the area of the semicircle.

Problem 2:

This problem involves a segment of a circle and asks for:

1. Length of the arc using the formula $L = \theta r$, where $\theta$ is the angle in radians and $r$ is the radius.
2. Area of the segment which is typically calculated by subtracting the area of the triangle formed from the area of the sector.

Problem 3:

It involves solving a trigonometric identity or expression, likely requiring simplification or proving an equation involving trigonometric functions.

Do you need a step-by-step solution for any or all of these problems? Please specify which problem you would like detailed help with.