A tunnel has a semicircular cross-section and a diameter of 10 m. If the roof of a bus
just touches the roof of the tunnel when
the bus is 2 m from one side, how high is
the bus?

this question is from the IGCSE maths student book1, shape and space 2 for Edexcel

If 20% of a number is 35, what is 50% of that number?

High schoolmathematics 5 points keith is the leading goal scorer for a team in an ice hockey league. last season, he scored 42 goals in 82 games. assuming he scores goals at a constant rate, what is the slope of the line that represents this relationship if the number of games is along the x-axis and the number of goals is along the y-axis?

In the figure below, ∠dec ≅ ∠dce, ∠b ≅ ∠f, and segment df is congruent to segment bd. point c is the point of intersection between segment ag and segment bd, while point e is the point of intersection between segment ag and segment df. the figure shows a polygon comprised of three triangles, abc, dec, and gfe. prove δabc ≅ δgfe.