Pentagon with x

Part of the Polygons & Quadrilaterals section of Coddy's Geometry journey. Lesson 54 of 61.

A board task can hide the letter in several angles at once. Collect the like terms after the rule writes the equation.

$Quadrilateral with angles x, 2x, 2x and x degrees$

Here the four angles of a quadrilateral make 360: x + 2x + 2x + x = 360, so 6x = 360 and x = 60. The angles are 60°, 120°, 120° and 60°. A right-angle square in the polygon adds 90 to the sum like any number.

Challenge

Pentagon ABCDE has a right angle at E and four angles labelled with x. Tap the angles, pick the rule that connects them, and solve the equation the board writes for x.

Then press Check.

Try it yourself

$Use the figure to find x$